We can do better.

The definition

What it looked like in me

Looking back, I had signs of systemic inflammation, like waking up with ankle joints that had stopped flexing overnight, every night, and had to be worked back into mobility. I had histamine and mast cell reactions that I had never had before, often waking up to a swollen face. And I wasn't me anymore, but I couldn't remember who I had been. I was defensive, "stuck" internally, melting down numerous times a day every day, and losing my ability to live the life I had built. None of these traits were what my personality had been most of my life. I couldn't hold unfamiliar processes in my head to learn new skills, and the skills I had were deteriorating. Because I had seen this growing up, my thought process was simply to figure out what the metabolic holes in autism were and support them. Back then the wording wasn't as precise. It was, "My autism is getting in the way of my autism." So the question became, what does autism look like in the body? As I understood the biochemistry more, my nutritional journey turned into a somatic one and learning why they're both equally important biochemically.

The question this site asks

3 sources

• Raymaker et al. (2020). "Having All of Your Internal Resources Exhausted Beyond Measure and Being Left with No Clean-Up Crew": Defining Autistic Burnout.
• Higgins et al. (2021). Defining Autistic Burnout Through Experts by Lived Experience: Grounded Delphi Method Investigating #AutisticBurnout.
• Systematic Review: Autistic people's experience of camouflaging and autistic burnout in relation to one another (2026).

The redox findings

Autism is full of subgroups except when it comes to redox markers, especially glutathione levels and SAMe to SAH balance. We generally have greater oxidative stress, lower glutathione, and reduced antioxidant capacity. That means our body is overwhelmed and we struggle with metabolic burdens. Metabolic burdens is a very broad definition, and what this site explores is how they impact autism uniquely. Stress is a metabolic burden, not a psychological one, and it's a burden on top of a body that is already struggling with oxidative stress.

Glutathione matters to autism because it's the body's master antioxidant, built from three amino acids (cysteine, glutamine, and glycine,) and its job is to neutralize reactive oxygen species and help detoxify compounds. We hear some about needing more glutathione, but I never made the connection on how much that meant my body was struggling, not just my brain, because I was used to dysregulation as a baseline. I didn't know any other options for existing. It was the overstimulation, the anxiety, the emotions that physically hurt my body, the rejection sensitivity. Those were the kind of symptoms that decreased substantially when I learned to address these areas and my nervous system started to regulate. Autism studies consistently find not just lower total glutathione but a lower reduced-to-oxidized ratio (GSH:GSSG), meaning what's there is already more spent than fresh, not simply lower in quantity. Now when I hear low glutathione, I immediately want to know why. What is placing this burden and what happens when the burden is decreased?

SAMe to SAH matters to autism because SAMe is the body's main methyl donor, used in neurotransmitter synthesis, gene expression, and DNA methylation. SAH is what's left after SAMe donates its methyl group, and it actively inhibits further methylation, so the ratio (not SAMe alone) is what tells you how much methylation capacity is actually available. It has a lot of influence over how we feel. Studies have already connected low SAMe with depression and mood disorders.

Standard nutrition was built for a different body

An end result with nothing in front of it

We are told we're low glutathione, take some, it helps. Take more to handle what? What is coming before the loss of our body's frontline defense?

8 sources

• Blood biomarker levels of methylation capacity in autism spectrum disorder: a systematic review and meta-analysisThis meta-analysis of 22 studies found significantly lower methionine, SAM, and SAM:SAH ratios, along with significantly higher SAH in individuals with autism. The authors concluded that impaired methylation capacity is consistently associated with autism.
• Folate-Methionine Cycle Disruptions in ASD Patients and Possible Interventions: A Systematic ReviewThis systematic review summarizes evidence that autism is associated with disruptions throughout the folate-methionine (one-carbon) cycle, including altered homocysteine, folate, vitamin B12, and methylation metabolites. It concludes that abnormalities in one-carbon metabolism are consistently reported across the autism literature.
• Metabolic biomarkers of increased oxidative stress and impaired methylation capacity in children with autismThis landmark study found lower SAM, lower SAM:SAH ratios, lower cysteine and glutathione, and increased oxidative stress in children with autism, providing some of the earliest evidence that methylation and antioxidant pathways are linked in autism.
• Metabolic Endophenotype and Related Genotypes Are Associated With Oxidative Stress in Children With AutismThis follow-up study confirmed abnormalities in methionine metabolism, transsulfuration, glutathione metabolism, and oxidative stress while also identifying genetic variants associated with these metabolic changes.
• Metabolic Imbalance Associated with Methylation Dysregulation and Oxidative Damage in Children with AutismThis study found deficits in antioxidant capacity and methylation that were specific to autism, along with altered methionine cycle metabolites, glutathione depletion, oxidative damage, and DNA hypomethylation.
• Oxidative stress marker aberrations in children with autism spectrum disorder: a systematic review and meta-analysis of 87 studies (N = 9,109)This meta-analysis of 87 studies found widespread evidence of increased oxidative stress and impaired antioxidant defenses in autism, supporting the increased demand placed on glutathione and one-carbon metabolism.
• Oxidative stress-related biomarkers in autism spectrum disorder: Systematic review and meta-analysisThis systematic review and meta-analysis found significantly lower glutathione, cysteine, methionine, and glutathione peroxidase, together with increased oxidative stress biomarkers, supporting disruption of both methylation and transsulfuration pathways in autism.
• Autism and Folate-dependent One-carbon MetabolismThis review explains the biochemical links between folate metabolism, methionine metabolism, transsulfuration, and glutathione synthesis in autism, arguing that these pathways function as an interconnected metabolic network rather than isolated abnormalities.

I use the metaphor of our bodies as a kitchen to explain important processes that I knew existed, but had never thought about how they applied to autism. Like a working commercial restaurant, where a balance of guests, food, deliveries, and stocking ingredients is important to maintaining function.

Everything that enters the body creates work

Autistic bodies seem to run that process harder, in three ways at once.

What I mean by that specifically is this: More mess gets made. An autistic nervous system sits in a state of alert most of the time. Staying alert costs energy, and burning energy produces waste. So a day that looks ordinary from the outside can generate a lot more cleanup than it would for someone else.

More mess arrives from outside the process. Autistic guts tend to have an unbalanced mix of bacteria, and some of those bacteria release compounds the body then has to deal with. That's extra work nobody ordered.

There's less to clean with. This is the part that's measured most consistently in the research: autistic people tend to have lower levels of the body's main antioxidant, glutathione, and what's there is more used up than fresh. The cleaning supplies are already low before the day starts.

More mess, more deliveries, fewer supplies. Any one of those is manageable. All three together means the cleanup keeps falling behind, and burnout is what I believe happens when it falls behind for long enough.

Production versus clearance

Oxidative stress is a consistent finding in autism. That means reactive (meaning damaging) molecules are made faster than the body can manage them. Ie, more mess than cleaning supplies and staff.

Normal metabolism produces a lot of metabolic waste: ROS (reactive oxygen species), damaged proteins, oxidized fats, worn-out neurotransmitters, sulfites, purine metabolites, reactive aldehydes, spent cellular components. The problem is not that reactive compounds exist. The problem begins when the workload consistently exceeds what the kitchen can clean.

The pantry

We need nutrients to do a job, not float around in the body, so that enzymes can use them and keep us healthy. Poor digestion, restricted diet, or a depleted food supply mean our pantry comes up empty.

A nutrient being present is not the same as a pathway working

What counts as demand, and what counts as capacity

My whole system is based around understanding what is being demanded of me and what creates capacity and balancing the two. This is how I healed.

Demand, the things that create work:

• sensory, cognitive, and social processing
• masking
• sympathetic and HPA activation
• ATP expenditure
• normal metabolism, digestion, exercise
• inflammatory signaling
• gut-derived compounds
• sulfites, aldehydes, purine turnover
• reactive oxygen species and lipid peroxidation
• cellular repair and clearance of metabolic byproducts

Capacity, the things that determine how much work can be handled:

• ATP production
• nutrient, amino acid, and cofactor availability
• enzyme activity
• purine recycling and de novo synthesis
• glutathione production and recycling
• methylation
• MoCo-dependent clearance
• gut-barrier integrity
• antioxidant capacity and redox balance
• mitochondrial function
• recovery and regulation

You won't recognize all of these yet. Every section that follows fills one of them in.

The equation

(I want to note that this is for burnout because profound autism gets more complicated genetically.)

2 sources

• The Gut Microbiota and Oxidative Stress in Autism
• Oxidative stress and antioxidant therapeutics in autism spectrum disorder: a biochemical and structure-activity relationship perspective

Fight-or-flight has a metabolic cost

HPA axis and sympathetic nervous system mobilize fuel the moment stress hits: epinephrine triggers glycogen breakdown and glucose release; cortisol drives glycogenolysis and gluconeogenesis. This is how we normally think of stress in the body.

What matters for autism uniquely is that fuel is then pushed into cells to make ATP.

Stress is the body spending stored fuel on demand, not only a feeling.

Spoons are ATP

When people say spoons, I hear ATP, which is our energy molecule. The energy anyone has in a day is finite, but ours seems to struggle significantly more.

ATP breaks down into something called purines, and what matters here is that purines require nutrients and enzymes to handle and recycle. Very specific nutrients and enzymes.

When rest or unmasking is offered as the cure, what I hear underneath is ATP conservation. What I now understand ATP conservation is, is lowering the purine load, by definition. If less ATP is required, then less ATP is broken down into purines, and fewer purines need to be handled by the body.

Studies show stress induces abnormal ATP release and dysregulates purinergic receptors. When you dive into autism and purines, there is a wealth of information because purine dysfunction and autism have been connected for a long time.

One line of this research was done directly in autism: the Cell Danger Response.

While the rest of the world associates stress with cortisol, associating it with purines let me address something specific to autism. Neurotypicals don't generally have purine pathway issues and this isn't a cure, but it was a way more helpful question.

2 sources

• Metabolic Features and Regulation of the Healing Cycle: A New Model for Chronic Disease Pathogenesis and Treatment (2018)
• A Review of the State of Purinergic Signaling and Psychological Stress

One molecule, many jobs

Inside the cell, energy. Outside the cell, danger.

When a cell senses danger, it shifts its metabolism away from growth and toward defense until the threat passes. This is ordinary, well-studied cell biology. One of the tools cells use to coordinate it is ATP, which we know as energy. What we don't hear is that it becomes a danger signal the instant it is pushed outside the cell. ATP gets broken down by the body into something called purines. That system, purinergic signaling, is ancient and conserved and known to be one of the necessary shifts that move the nervous system into fight or flight.

So inside the cell, ATP is energy. Outside of the cell, it's a danger signal that is part of the start of a cascade of signaling in the body that we know as fight or flight.

The Cell Danger Response

Dr. Robert Naviaux named this response the Cell Danger Response, and proposed that in some chronic conditions, including autism, it never fully switches off. He did the research showing we're always in fight or flight, which matches our experience. What drew me to his work is that he traced the whole cascade of metabolic events that follows when cells sense a threat. Earlier research had shown that stress depletes nutrients. Naviaux mapped the full spread of damage. Calcium shifts inside the cell. Sulfur drains away. Nutrients are depleted, and others, vitamin D among them, become unusable even when they're present. He did it with real specificity, which makes the work worth reading in its own right. At the start of the cascade, purines change the meaning of ATP, turning it from an energy signal into a danger signal.

His research did flag that there are numerous times in development that a human body is supposed to shift out of fight or flight and autism doesn't do that. It brings more evidence to our experience of our baseline being a higher level of stress. He did test a medication called Suramin (which blocks the purine receptors) in mouse models, and then in a small placebo-controlled trial. Lowering the ATP danger signal temporarily in autistic children eased core autism features like being nonverbal, which returned as the effect wore off.

The drug is not the point in me bringing this up. The point is the principle underneath it: when the danger signal was lowered, features that looked fixed changed. That points toward a metabolic state that can move, not fixed wiring, at least in some of us. Essentially, what went down can come back up, which is the hope I needed to heal burnout. It also highlighted for me that purines can be a powerful influence and one for me to understand more.

Note about Suramin: Suramin has toxicity issues with long-term use. Naviaux wants to use a low dose with autism, but I question if there are too many other factors at play to have that be effective longer than the medication is in the system. Genetics in autism range from ones that impact the brain to metabolic genes to mitochondrial damage, not to mention lead being another cause. It feels like he's not appreciating the diversity of genetics and reasons behind autism. I write this for burnout because the more studies I was exposed to, the more I understood how wide our differences could be. I struggle to understand how shutting off purines alone could have the impact he claims on the entirety of autism. I think purines are incredibly relevant to burnout, though, and his work helped me understand that pathway more.

How to use the alarm and the brake being in the same pathway during healing

One of the reasons I became so interested in purines is that the same pathway that starts the alarm also contains the brake. Purines get broken down in the body into other molecules as our system metabolizes them. Xanthine, a purine breakdown product, creates reactive oxygen species, fragments mitochondria, and runs high in adults with anxiety. The enzyme that makes uric acid also throws off ROS (reactive oxygen species) as it works, so purine breakdown is itself a direct source of oxidative stress that eats glutathione. This goes back to where I described the body as a kitchen that creates messes as part of its normal function. You want purines, you want them to be broken down, but you also want your body to be able to clean up the mess.

The breakdown of purines goes ATP → ADP → AMP → adenosine → inosine → hypoxanthine → xanthine → uric acid. So two of the steps necessary to handle purines in the body produce oxidative stress (xanthine and uric acid). The more purines the body handles, the more oxidative stress is created that needs to be cleared. More stress = more oxidative stress. Rest removes that burden temporarily, letting the body start to catch up. It does not support the whole process.

The pathway also has a brake called adenosine, which is an inhibitory signal that builds up when a cell has been working hard, promotes sleep, and lowers anxiety. Nudging adenosine up, including through movement, is beneficial metabolically. Adenosine's importance is best explained through its role in seizure conditions. In many seizure conditions, adenosine is broken down too quickly by the body and, when absent, seizures occur. Seizure medication is commonly based around slowing down the enzyme that breaks down adenosine so it stays in the system longer and reduces seizure activity. Keto diets do the same thing through epigenetic changes that happen when you switch from glucose as an energy source to fat.

The alarm and the brake share one system depending on how you support it, which now makes sense when I look at those of us who stay regulated through heavy activity. I wear a Garmin to monitor sleep, and the longer I go without exercise, the more my sleep deteriorates. It's proposed that adenosine rises when ATP is depleted, meaning intense exercise is necessary. However, what counts as intense exercise is directly related to how much ATP you have. I tried to exercise when I was deep in burnout and it was not effective. It's only now that I have spoons that I use exercise to improve sleep, and that was a gradual increase. Burnout greatly damaged my ability to exercise and required pretty extensive rebuilding.

The theory is that intense exercise depletes cerebral energy stores (ATP), and the resulting adenosine/inosine accumulation is part of what builds sleep pressure afterward, with sleep then serving to replenish those high-energy compounds. So the causal chain is: intense exertion → energy store depletion → adenosine rises → binds A1 receptors in the basal forebrain → suppresses wake-promoting neuronal activity → increases sleep pressure. This was helpful to understand for when and what exercise to introduce during different stages of healing.

Purines and autism

The relationship between purines and autism isn't a recent discovery.

Purines are all over autism. ADSL deficiency, which is part of the purine pathway, is the only genetic deficiency that presents as autism and not just autism as a feature. In other words, a genetic ADSL deficiency is the only metabolic gene, to my understanding, that creates autism 100% of the time. ADSL is part of the de novo purine synthesis pathway, meaning it obstructs the body's ability to create purines. Patients with it develop a spectrum of neurological presentations even though other pathways remain intact.

In 1964, researchers first described what became known as Lesch-Nyhan syndrome, a disorder later shown to result from deficiency of the purine salvage enzyme HGPRT. The discovery demonstrated that disruption of purine recycling can profoundly affect brain development and behavior, establishing one of the earliest links between purine metabolism and neurological disease.

These disorders are rare and are not what I believe explains autistic burnout. They showed me something much simpler: when purine metabolism is disrupted, the nervous system can be profoundly affected. Purines are signaling molecules in addition to be energy molecules, regulating synapse formation, neuronal migration, axon growth, neurotransmitter release, microglial activation, sleep and wakefulness, seizure threshold, and neural excitability.

Outside of genetics, one of the strongest findings across autism metabolomics in studies is that purine metabolism is commonly disrupted.

A 2023 multi-omics study integrated metabolomics and transcriptomics to examine purine metabolism in autism spectrum disorder. The researchers found consistent evidence of dysregulated purine metabolic pathways, including altered levels of purine metabolites such as uric acid, inosine, and hypoxanthine, along with differential expression of purine metabolism-related genes. They concluded that purine pathway dysfunction is a common feature of ASD and suggested that blood uric acid may serve as a potential biomarker for autism while supporting purine signaling as an important biological pathway involved in ASD.

A 2024 metabolomic and metabolic network study compared blood samples from newborns who later developed autism with samples from 5-year-old children with autism. Among the fifty biochemical pathways examined, purine metabolism showed the greatest developmental disruption, including altered regulation of xanthine and other purine metabolites. The authors concluded that abnormal purine metabolism is present before diagnosis and remains dysregulated throughout early childhood, supporting a role for purinergic signaling and mitochondrial metabolism in ASD.

A 2016 urinary metabolomics study also identified abnormal levels of multiple purine metabolites in autistic children and proposed that disturbances in purine metabolism contribute to the metabolic dysfunction observed in ASD.

I get why Naviaux looks to purines to cure autism, even if I don't agree with Suramin as a solution and generally question if he's taking all of autism into consideration. My interpretation is that if there's room for purines as a cure, there is most certainly room for purines as a solution to our burnout. The reason I pull nutrition into this is that deficiencies can disrupt the enzymes involved in these pathways, especially when they're already compromised and overwhelmed. Enzymes need nutrients to function. It may not bring enzyme function or the pathways to 100%, but a deficiency only makes the situation worse. And deficiency is defined by need, which is increased in a group of people under constant stress. There's a lot more happening in us than the RDA accounted for.

The purine pool measured directly

Why this matters more than one more low number:

Everything else I cite about purines is measured downstream, in urine metabolites or serum uric acid. Those tell you what's excreted when ATP has been converted over many steps and is ready to leave the body.

What this measured is the pool itself, inside the cell, and it's sparse. That distinction is important. If the clearance end were the whole story, you'd expect breakdown products backing up while the original source pool stayed intact. A traffic jam, not a shortage. Low adenine says something different: the route to replacing spent ATP is short on its raw material, which forces more building from scratch, which costs the ATP and the folate that section 6 is about. That's the mechanism I've been describing being measured rather than inferred.

Purines aren't only energy. I talk later about an enzyme called MoCo in regards to autism, and MoCo synthesis begins with GTP and BH4 comes from GTP as well. So a thin purine pool doesn't just mean less ATP. There are two parallel routes that ATP breaks into (both considered purines). One starts with GTP and one involves adenosine, what was measured. It means less of the material available for the clearance system (the MoCo enzyme) itself is built from, and less of what dopamine and serotonin synthesis depend on (BH4). Less actual energy, worse clearance of metabolites, fewer happy mood chemicals.

Low uric acid may be another clue

Why this changed how I viewed burnout

The pathway that coordinates energy, danger signaling, antioxidant production, and stress recovery is also one of the pathways most consistently disrupted in autism. I have no way of knowing if it is in me. I want to be very honest that I operated from the assumption that it applied to me before I assumed that it didn't. I've seen burnout spiral into more extreme consequences, including within my family. That means I'm comfortable taking more risk to avoid extreme consequences, and I am my favorite guinea pig. I don't expect others to do the same, but I want to be honest about that and supply the information I've learned so people can ask questions that might be more helpful in their healing. I believed I had seen how much worse it could get, and I went all in. I wasn't interested in being conservative. I was interested in surviving.

Supporting those pathways nutritionally was vital to me. Nutrient depletion on top of a disrupted pathway means even more disruption. I also put more weight on learning modalities like breathwork to give me tools to use in the moment. I'm still learning to stay regulated in a wider range of situations, and it's turning into an incredible way to explore life.

This doesn't prove purines cause burnout. It does ask the question of if autistic people may begin with a system that is already less efficient at processing the metabolic demands of stress, and there is currently no specific-enough research on burnout or Level 1 to know. Level 1 would theoretically have the least dysregulated pathways, which is why it takes years of accumulation until we finally start breaking. It also leaves room for nutritional and somatic support to have the most impact. As I'll go into later, the support I needed was not at all what I thought it was before I did this work.

10 sources

Cell Danger Response

• Metabolic Features and Regulation of the Healing Cycle: A New Model for Chronic Disease Pathogenesis and Treatment (2018)

Purinergic Signaling

• Purinergic Signalling and Neurological Diseases: An Update
• Purinergic Signalling: Its Unpopular Beginning, Its Acceptance and Its Exciting Future

Purine pathway dysfunction

• Purine Signaling Pathway Dysfunction in Autism Spectrum Disorders: Evidence From Multiple Omics Data (2023)Also the source for uric acid as a proposed biomarker.
• Metabolic Network Analysis of Pre-ASD Newborns and 5-Year-Old Children With Autism Spectrum Disorder (2024)
• Urinary Metabolomics Analysis Reveals Abnormal Tryptophan and Purine Metabolism in Children With Autism Spectrum Disorder (2016)

Historical evidence

• A Familial Disorder of Uric Acid Metabolism and Central Nervous System Function (1964)
• An Infantile Autistic Syndrome Characterised by the Presence of Succinylpurines in Body Fluids (1984)

Uric acid

• Metabolomic Changes in Children With Autism Spectrum Disorder (2024)

The purine pool measured directly

• An impaired glycolysis induces ATP deficiency and reduced cell respiration in stem cells of patients with autism spectrum disorders (Féron et al. 2025)Metabolomics on olfactory stem cells from 8 ASD patients found adenine lower in all 8 and ADP lower in 6 of 8, alongside reduced pyruvate and glucose-6-phosphate. Same cohort as the 2016 MOCOS study; the 8 selected were the most severely affected.

Two ways to get purines

Purines are valuable molecules, so the body tries not to waste them. The body gets purines two ways: salvaging old ones, which is easier on the body, and building new ones from scratch, which is expensive. Building new requires six enzymes and needs a folate-derived one-carbon unit at two steps, the amino acids glycine, glutamine, and aspartate, the starter PRPP, and a great deal of ATP.

When recycling works well, the body conserves both energy and nutrients. When it doesn't, more purines have to be built from scratch. That requires additional ATP and folate, making the process metabolically expensive.

If recycling is slow, you cannot replenish ATP fast enough, and your energy, methylation, and DNA building all suffer. Too fast and you flood the system with breakdown products, which is where gout starts showing up. A small percentage of us have the too-fast issue that produces gout, but that is a subsection of autism.

Purines depend on folate

So here is where nutrition is uniquely and incredibly important:

One of the things that surprised me was how closely purine metabolism and folate metabolism overlap. I only found this when I started digging into details, trying to make a better system for me to follow for my health. I hadn't expected the two pathways to meet here at all. Two steps of the purine assembly line require folate. What that means is a purine problem and a folate problem can look remarkably similar to the cell.

There was, in fact, a study that modeled exactly this: knocking out the purine genes produced nearly the same fingerprint as a simulated folate deficiency. (Geryk et al. (2020), "The Key Role of Purine Metabolism in the Folate-Dependent Phenotype of Autism Spectrum Disorders: An In Silico Analysis.") They modeled knockout of six purine-synthesis genes (GART, PFAS, PPAT, PAICS, ATIC, ADSL) and found it produced nearly the same metabolic blockage pattern as simulated folate depletion.

I'm not implying that a folate deficiency causes autism. I'm saying that a folate deficiency can make our ability to handle stress through purine metabolism worse.

This is part of how burnout got redefined for me

Purines help coordinate energy production, danger signaling, DNA and RNA synthesis, folate metabolism, antioxidant production, sleep, and recovery. When that system is functioning well, the body can respond to stress and then return to normal physiology. There's also a real mechanistic basis for a theoretical vicious cycle here. Folate cofactors are a shared, limited pool competed for by three processes at once: de novo purine synthesis, thymidylate synthesis, and homocysteine remethylation. If purine demand rises, because recycling isn't keeping up and more has to be built from scratch, it pulls folate away from the other two processes, straining methylation and DNA synthesis capacity from a different direction. That's a genuine feedback structure, not just two separate problems running in parallel.

When it struggles, every stress response theoretically becomes metabolically more expensive. Right now our narrative around folate has to do with helping anxiety and that in some of us, folate to the brain is blocked. This broadened folate for me dramatically. I took all this as I really didn't want to be folate deficient and be autistic. There's too much at stake, at least for me.

Looking at the pathway this way changed how I thought about burnout. Purines aren't simply producing energy. They are participating in nearly every phase of the stress response, from creating energy to signaling danger to supporting recovery afterward.

Before learning about purines, I associated burnout was mostly about running out of energy. My experience was much more extreme, but that's the narrative I hear most. Now I think it as placing repeated demands on a metabolic system responsible for much more than energy production, which fits my experience better.

2 sources

Purine metabolism and folate

• The Key Role of Purine Metabolism in the Folate-Dependent Phenotype of Autism Spectrum Disorders: An In Silico Analysis (2020)
• How Environmental and Genetic Factors Combine to Cause Autism: A Redox/Methylation Hypothesis (2008)

Folate feeds two systems we cannot afford to lose

The common narrative is MTHFR does not cause autism but we all have it so take methylfolate, it improves neurotransmitters, anxiety, and you've done well. I started there, then went deeper. What I think is important to know is that once folate is in a usable form, it can be used in two directions, and both are commonly depleted in autism.

• Toward SAMe, the body's primary methyl donor, used in hundreds of reactions: neurotransmitter synthesis, gene expression, inflammation control. Without enough SAMe, methylation falters and a lot of downstream processes feel it.
• Toward glutathione, the master antioxidant and detox molecule that handles oxidative stress, supports immunity, and is critical for repair.

One way to hold it: SAMe helps the body run its processes, and glutathione helps it survive the damage done while running them. Supporting them takes more than folate. SAMe in full needs folate, B2, B6, B12, zinc, and magnesium. Glutathione needs glutamine, cysteine, glycine, B6, B2, and selenium. It was never as simple as one pill. That being said, every study I've seen giving multivitamins to autism have shown improvement. The bigger picture of what I needed to support myself did untangle with grit, patience, and time.

MTHFR, folate deficiency, and which folate

The 98% MTHFR figure from blogs isn't in the research that I found. In fact, I found no clean prevalence number. Folate deficiency, often tied to restricted eating, appears more common than the mutation. Low folate is what I care about, however it happens.

I had to unlearn "I eat well so I get enough." Every time I supplemented, I improved. Our food is depleted and the RDA doesn't account for a healing body, a dysbiotic gut, fight or flight, or chronic inflammation. This is what frustrates me about the idea of what "enough" is. I ate "well" and I still didn't get enough nutrients.

Folic acid started being added into our food in 1998. It is also what is commonly found in most multivitamins. Folinic acid can be bought over the counter or given in prescription form called Leuvoceryn and is given specifically to replete folate levels in the brain because it's better at crossing the blood brain barrier. Methylfolate is what we seem to hear about the most, and it has its use but does not cross the blood brain barrier as well.

Folic acid, folinic acid, and methylfolate aren't interchangeable, and the difference comes down to which enzyme each one needs to become usable. Folic acid has to pass through DHFR (dihydrofolate reductase) before the body can use it. DHFR is slow and easily saturated, so a high dose of folic acid just leaves the extra circulating in the blood, unmetabolized (UMFA). Folinic acid skips DHFR entirely and enters the cycle further downstream, which is likely why it works more reliably for people whose DHFR conversion is sluggish. Methylfolate is already the finished, active form, so it doesn't need DHFR or MTHFR at all, but it does need B12 to hand its methyl group off; without enough B12, it can get stuck in that form instead of cycling through.

Both folinic acid and methylfolate bypass the MTHFR variant, so they are equal there, but not elsewhere. In one comparison, people with the MTHFR 677CT genotype lowered homocysteine more on folinic acid than on methylfolate, and folinic acid may support DNA synthesis and rapidly dividing tissues differently because of where it enters the cycle. I've met people that say they can't handle folinic acid but handle methylfolate better, but some people don't handle methylfolate well. It does a good job at adding methyl groups for the body to use, which can cause anxiety for some.

The critical detail: folinic acid alone did not meaningfully improve methylation or glutathione markers. It only moved them when combined with methylcobalamin, a specific form of B12. If you are taking folinic acid hoping to feel better, the combination is what moves the needle, not folinic acid by itself.

When I dug further, I think there are important questions to be asked when it comes to giving and taking any form of folate. Studies have found that greater intake of folic acid has been connected with dementia. This is where the dementia question comes in. A 2024 UK Biobank study of over 466,000 people found folic acid supplementation linked to higher Alzheimer's and vascular dementia risk. The proposed mechanisms are specific to folic acid: UMFA buildup, and folic acid masking an underlying B12 deficiency that then goes uncorrected. None of the dementia research I found implicates folinic acid or methylfolate specifically. So this looks like a folic acid problem, not a folate problem, but we don't know. Low folate still raises dementia risk generally. Since we're commonly given high levels of folinic acid and many of us take methylfolate, are those versions raising or correcting a dementia risk? Or something else?

1 source

• Effectiveness of methylcobalamin and folinic acid treatment on adaptive behavior in children with autistic disorder is related to glutathione redox status (Frye et al. 2013)Source for the point that folinic acid moves methylation and glutathione markers in combination with methylcobalamin rather than on its own, and that improvement tracked glutathione redox status.

Again, I'm asking for better questions in the name of our health

Autism homocysteine findings are inconsistent in which direction they go. Most find high homocysteine, some find low. What they don't find is normal. There's clearly support that's consistently missing because its inconsistency isn't able to be used toward a cure. But if it's inconsistent, it means something for our health down the road. Problems in autism are consistently ignored because they're not consistent across us even if they're consistently wrong, but that doesn't make them meaningless for our health. We deserve to know about these deviations so we can take care of ourselves. Homocysteine is connected with a myriad of health conditions. Support is always a better option than correction once damage is done.

Protein comes first

Methionine is essential. The body can't make it. It comes from protein. You have to eat protein, full stop.

If protein intake is low (restricted diet, poor appetite, GI problems), the homocysteine cycle (among others) are constrained at the first step before folate, B12, B6, or any enzyme gets a chance to matter.

I struggle to eat enough protein at times. My solution to this is denatured whey, which I can throw into a drink if I end up skipping a meal, or two some days.

3 sources

• Metabolic biomarkers of increased oxidative stress and impaired methylation capacity in children with autism (James et al. 2004)
• Autistic Children are Three and a Half Times More Likely to Have High Homocysteine (citing Narayan et al.)
• Blood homocysteine levels in children with autism spectrum disorder: An updated systematic review and meta-analysis

Some amino acids become essential under conditions we already live in

Autism isn't an acute illness but checks the boxes the category is built around: sustained oxidative stress, sustained metabolic demand, inflammation from LPS and dysbiosis (I go into this later).

Glutathione is built from three of the conditionally essential amino acids - cysteine, glycine and glutamine. Dopamine needs tyrosine and nitric oxide needs arginine. "Just take glutathione" supplements the end product without addressing the supply problem, or why demand is elevated. I found benefit at certain points to add tyrosine to supply enough dopamine, and now I'm using citrulline to improve nitric oxide. All of these I would be told I didn't need, and all of them turned into tools at various points.

2 sources

• Essential Amino Acid (ScienceDirect Topics overview, conditionally essential amino acids)
• The Low-Down on Conditionally Essential Amino Acids

Even the cofactors have to be activated: B2

One study describes functional B2 deficiency in autism, meaning we had B2 but it wasn't being used. There is possible bias here and needs follow-up, but considering B2's role in energy production, purine pathway, and glutathione, it's worth more than a casual mention. B2 became an essential vitamin for me.

Riboflavin isn't usable on its own. Riboflavin kinase makes FMN (needs zinc). FAD synthetase makes FAD (needs magnesium). Both cost ATP, so B2 alone won't do it.

What FAD/FMN run: Complex I and II of the electron transport chain (where ATP is made), glutathione reductase (recycling glutathione), MTHFR, xanthine dehydrogenase (purine breakdown; also needs MoCo, which I go into later). Energy, antioxidant recycling, methylation, purine handling, one cofactor.

I took R5P, the form that does not need conversion. I also took the cofactors for B2, which are selenium, molybdenum, and iodine. Selenium is needed for glutathione production, and molybdenum I actually tested deficient on several times, even after supplementing.

2 sources

• Riboflavin Kinase (ScienceDirect Topics overview)
• Flavine Mononucleotide (ScienceDirect Topics overview)

What autistic dysbiosis looks like

Bacteria can both harm and help us. They are a source of vital B vitamins, some consume toxic metabolites, and some produce toxic metabolites. They can help or harm barrier function. And which ones we have are unique in all of this. All of this changes the burden we can tolerate and our capacity.

Dysbiosis changes what enters the system, what must be cleared, and what nutrients are available. We are defined as having lower diversity, more potentially pathogenic organisms (Shigella, Klebsiella, Clostridium), and less beneficial bacteria like Faecalibacterium and the lacto and bifido bacteria. There are studies that explore clostridia's effect on the brain and speculate that it may play a role. I've had gut testing done and I don't have clostridia. Below are the commonalities I did find and why addressing them made a difference.

3 sources

• B Vitamins and Their Roles in Gut Health (2022)This review catalogs the major gut bacterial species capable of synthesizing each B vitamin and summarizes the biosynthetic pathways involved. The authors conclude that gut microbes are an important endogenous source of B vitamins and that microbial vitamin production helps support both the microbiome and host physiology, including energy metabolism, neurotransmitter synthesis, immune function, and intestinal health.
• Precision synbiotics increase gut microbiome diversity and improve gastrointestinal symptoms in a pilot open-label study for autism spectrum disorder (2024)This metagenomic study compared the gut microbiomes of 296 individuals with autism to 123 neurotypical controls. At baseline, the autism group exhibited lower gut microbial alpha diversity, increased proportions of potentially pathogenic bacteria (including Shigella, Klebsiella, and Clostridium), and reduced levels of beneficial microbes such as Faecalibacterium. After three months of precision synbiotic supplementation, microbial diversity increased and gastrointestinal symptoms improved. The findings support the presence of gut dysbiosis characterized by reduced microbial diversity and depletion of beneficial bacteria in autism.
• Altered composition and function of intestinal microbiota in autism spectrum disorders: a systematic review

LPS: not a problem until the barrier leaks

Something called a lipopolysaccharide (LPS) sits in the outer membrane of gram-negative bacteria. It has three parts, one of which is toxic, called Lipid A. Old studies called LPS "endotoxemia." When bacteria die, this toxic part is released into our gut. Behind a healthy wall, it is normal physiology and passes through our system. Through a permeable wall, it is inflammatory because it enters our bloodstream.

LPS is one of the best-studied links between leaky gut, behavior, and neuroinflammation. I cannot emphasize that enough. LPS is widely studied and known to be extremely inflammatory because it activates the human immune system. Everyone has it. The difference is degree: more gram-negative bacteria in autistic microbiomes, and we have a more permeable wall for it to cross.

I did testing as I started to heal and more recently, so several years apart. I was very proteobacteria heavy at the start. I am less so now, but still more than ideal. My gut health has tracked with my symptoms and overall health.

I was introduced to LPS through a website, not studies, and I addressed it mildly early. It helped me feel a little better. I did notice considerable changes in how much body heat I emitted (as did my situationship) and how I interpreted temperature. It wasn't until later that I understood its importance and addressed it more thoroughly. This is an area that the studies I wanted didn't exist, but if we were known to have more gram-negative bacteria and known to have a permeable gut, it was an area I was curious about.

Link: Microbial Influence

How it gets through

The leaky wall. Gut permeability. And fat. There are two routes.

What LPS does once it's in

Activates immune signaling. Increases oxidative stress. Stimulates extracellular ATP release, which adds purines to the danger signal we already experience on a pathway that may be struggling. Studies have found that blocking two purinergic receptors reduces LPS inflammation, so the inflammation is showing itself partly through purine receptors.

Stimulates nitric oxide; in chronic inflammation NO plus superoxide makes peroxynitrite, which damages mitochondria and oxidizes BH4.

Promotes lipid peroxidation, which generates reactive aldehydes.

Immune cells responding to LPS produce sulfite.

Depletes zinc. Hits the liver first. Crosses the blood-brain barrier. Suppresses oxytocin. Diverts tryptophan into quinolinic acid.

Impacts thermoregulation. This was my initial impression of the impact it had early on, is that it changed how I experienced temperature and how others experienced my own body temperature.

What I think is especially interesting is chronic LPS symptoms look like burnout: fatigue, brain fog, social withdrawal, anhedonia, altered thermoregulation.

As of 2025, there is a systems hypothesis paper (vitamin transport suppression, metabolic reprogramming) that covers most of what I found. What I'd add is that LPS is landing on a body with the weaknesses I've already described. This is LPS on a neurotypical body. This is LPS on a body that has unique weaknesses in the areas that LPS inflammation impacts.

As an interesting note: Suramin (what Naviaux wants to give autistic kids) kills candida extremely well and blocks purinergic receptors. It kills candida because fungus love purines, so blocking purines receptors removes their food source. This makes me wonder how much of the Suramin response was removal of inflammation response from LPS. Like I noted above, there is already a study that found blocking two purine receptors removed the inflammation response from LPS, which is a fascinating and unexplored connection.

LPS doesn't only add to the pile. It cuts the supply line.

This 2025 systems paper proposes the same thing is happening in the autistic brain. Analyzing postmortem cortex, it found both transporters modestly downregulated alongside suppressed glycolysis and mitochondrial enzymes, and argues chronic LPS exposure is the upstream trigger.

Look at what those three cofactors run: thiamine and lipoic acid are both required by pyruvate dehydrogenase and α-ketoglutarate dehydrogenase, the two complexes that stand between glucose and the energy the rest of this site is about. Pantothenic acid becomes CoA. These are the same enzymes sulfite damages by destroying thiamine and aldehydes damage by attacking lipoic acid. Three different routes, one target.

So LPS raises the workload and lowers the ability to do the work, at the same time, through the same exposure. That's both sides of the equation from one source, which is not something anything else on this site does.

What I'd hold onto here: this is a hypothesis paper. Single author, secondary analysis of twelve postmortem brains against twelve controls, no formal statistical testing, and expression differences of three to five percent. The title asks for validation rather than claiming it. What's solid is the underlying gut-epithelium work on LPS and the transporters; what's proposed is that it happens in the brain too, and that it's happening in autism. This is why, even though the research hasn't gone where I wanted, I took LPS and my gut health very seriously; and it worked extremely well. But I did it very specifically, because I knew what I was binding. I've done testing. I don't have a heavy metals problem. However, knowing my gut bacteria makeup, I probably do have a LPS problem.

4 sources

LPS and cofactor transporters

• A Systems Hypothesis of Lipopolysaccharide-Induced Vitamin Transport Suppression and Metabolic Reprogramming in Autism Spectrum Disorders: An Open Call for Validation and Therapeutic Translation (Dervishi 2025)Secondary analysis of postmortem cortex (12 ASD, 12 control) proposing that chronic LPS exposure suppresses the multivitamin transporter SLC5A6 and the thiamine transporter SLC19A2, limiting cofactor availability alongside downregulated glycolysis and mitochondrial enzymes. Explicitly a hypothesis paper calling for validation.
• Lipopolysaccharide inhibits colonic biotin uptake via interference with membrane expression of its transporter: a role for a casein kinase 2-mediated pathway (Lakhan and Said 2017)The experimental basis for LPS suppressing SLC5A6, in gut epithelium.
• Bacterial lipopolysaccharide inhibits colonic carrier-mediated uptake of thiamin pyrophosphate: roles for TLR4 receptor and NF-κB/P38/JNK signaling pathway (Anthonymuthu et al. 2023)
• Bacterial lipopolysaccharide inhibits free thiamin uptake along the intestinal tract via interference with membrane expression of thiamin transporters 1 and 2 (Anthonymuthu et al. 2024)

2 sources

• Identification of Bacterial Lipopolysaccharide-Associated Genes and Molecular Subtypes in Autism Spectrum Disorder
• ATP released by LPS increases nitric oxide production in raw 264.7 macrophage cell line via P2Z / P2X7 receptors

Stress opens the wall

1 source

• Stress and the Gastrointestinal Barrier: Regulation by the HPA AxisReviews evidence that chronic stress and cortisol disrupt intestinal tight junctions, increasing gut permeability and facilitating LPS translocation.

Stress changes who lives there

3 sources

• Effect of psychological stress on the oral-gut microbiota and the potential oral-gut-brain axis
• Exploring the complex relationship between psychosocial stress and the gut microbiome: implications for inflammation and immune modulation
• Psychological stress disrupts intestinal epithelial cell function and mucosal integrity through microbe and host-directed processes

LPS activates mast cells directly

My burnout had some stellar mast cell problems. Not all of us do, but mine did.

2 sources

• Regulation of allergic airway inflammation through Toll-like receptor 4-mediated modification of mast cell function
• Lipopolysaccharide enhances FcepsilonRI-mediated mast cell degranulation by increasing Ca2+ entry through store-operated Ca2+ channels

The question nobody has asked

Studies show our gut is permeable, but they tend to track zonulin. Studies show we over-respond to LPS when given it, with one subgroup responding in a more extreme manner than the rest of us. One study measured LPS directly, in profound autism, and found a correlation.

The studies measure the response. What if we asked whether the trigger was already there? Do all of us have it? I also have a response to LPS only being measured in profound autism, and that is that profound autism is the most likely to have more extreme genetics impacting them. With what I know now, I would question the impact the gut dysbiosis is having in terms of them being profound. Is it impacting their health? Any LPS in their blood stream is going to have an impact on their health. Is it impacting their autism significantly, which was probably the original question...there's probably other genetics making a larger impact. One of the groups I would look to for an LPS problem most would be undersupported, highly-stressed Level 1 autism, purely based off the impact stress has on the gut and the cycle we get stuck in.

Reactive compounds are not toxins until they pile up

The study

There was a small study that took olfactory stem cells from eleven autistic adults and eleven controls. Why olfactory stem cells: they reflect very early development, one of the closest windows into the period autism is thought to begin.

For a study this small, 8 of 11 stood out. Most autism-associated genes appear in small subsets. One article has called this finding the first gene strongly associated with autism, and my hope is that they follow up on a wider population. Because the study was so small, I had to track each enzyme pathway down individually to understand how much weight I felt comfortable giving it.

Four enzymes, three queues you already know

If you look at the input for each of those enzymes, purines seem to cover a more emotional, somatic sphere...and the gut, including food intake. Aldehydes are found extensively in the gut and the environment. Sulfites are also found extensively in the gut, but I think of them as the preservatives you find in food, which is extremely common now. You have an enzyme that handles emotions (purines), the world (aldehydes), and our food (sulfites), all in one. It is the core of where we become the warning bell to the world, the canary in the coal mine. A down regulation of what handles these inputs means we struggle first when these areas become unsustaining. It's absolutely fascinating and turned healing into a life-changing endeavor purely by how many areas it touches.

What happens when the cofactor is short: the hospital case

What MOCOS does and doesn't touch

There is no binder for aldehydes, sulfites, or purines. Detoxing them had a very different route.

The 2025 follow-up: reduced ATP, from impaired glycolysis

Further findings found that adenine lower in all eight patients, ADP lower in six of eight, pyruvate lower in all eight, glucose-6-phosphate and ascorbic acid lower in most. Enolase 2 altered in all eight, plus glucose transporters and several other glycolytic genes. Research on this area, for as small as the population is, keeps coming up incredibly consistent across all of the participants.

So does the glycolysis problem come from MOCOS?

I'm not claiming MOCOS causes the ATP deficit. I'm saying two findings that compound each other were found in the same eight people, and either one makes the other harder to carry.

The original study was eleven people. The eight people in the 2025 follow-up study were selected as the most severely affected in the cohort, classified Level 3. The two participants considered Asperger's were not among them, unfortunately.

Why nutrition matters to MoCo

MoCo highlights how the RDA needs to be reconsidered for us

Building MoCo needs molybdenum, copper, iron-sulfur clusters, SAMe, zinc, magnesium, L-cysteine, and P5P.

The molybdenum RDA studies were done poorly. Here's specifically why: the current RDA for molybdenum is based on a total of four young men in 1995. Four. That's the entire human evidence we base the current adult RDA for molyb on, and none of those four were autistic, none were dealing with a heavier MoCo enzyme burden, and none were living with chronic gut dysbiosis. Out of those four, one of the men did show signs of his system struggling with the low amount. They also tried a higher amount, over 1 mg, with none of the men struggling. They chose to double the lower amount and call it a day, which is how we got the 45 mcg RDA. The RDA for women is math based off of the findings of four men. Molybdenum is also not available in processed or canned foods. You have to eat fresh food to get it or supplement. This is why I was genuinely deficient. You don't need a lot, but you do need it.

Sulfur is another area the RDA fails us, but I want to note sulfur is complex in autism so I don't want to encourage taking high amounts without understanding how you respond. Sulfur is a mineral I don't widely hear considered for us, yet studies have shown and are very well aware of autism being sulfate deficient. Some of us have genetics that waste sulfur, some of us have slow CBS genetics where too much sulfur is a problem, and some of us don't have either. This is why I bring it up cautiously.

There is no RDA for sulfate/sulfur at all. The Institute of Medicine looked at the evidence and explicitly declined to set one, reasoning that sulfur amino acid intake alone should cover it. But the researchers who actually study sulfur balance directly have pointed out a real gap in that reasoning: the existing amino acid requirements were only ever tested for their ability to maintain nitrogen balance, never sulfur balance specifically, and sulfur-balance testing "has never been done, neither in humans nor animals." Even the original studies behind the methionine RDA were run on groups of three to six people per amino acid. Studies in autism have shown we are often sulfur deficient and transsulfuration pathways are often an issue in us. Sulfur is complex in autism, but it's another nutrient that many of us experiencing burnout need to be aware of to heal well.

3 sources

• Molybdenum - Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc
• Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate (Institute of Medicine, 2005), Chapter 7: Sulfate
• Are we getting enough sulfur in our diet?

Why LPS lands harder here

2 sources

Molybdenum deficiency

• Molybdenum Deficiency (Merck Manual, Professional Edition), citing Abumrad et al. 1981
• Molybdenum Deficiency - an overview (ScienceDirect Topics)

The SUOX enzyme converts sulfite, one of the body's most reactive sulfur compounds, into sulfate, a stable nutrient the body can use. That conversion helps supply us with necessary sulfur to use for numerous processes, and without the conversion happening, it may be impacting areas we don't realize. I haven't found a good nutritional supply of sulfur that matches the conversion that happens in our body. The closest our body can use chemically is Epsom salt, which isn't meant to be ingested. One study specifically suggests it to bridge that gap in autism, but unfortunately there's no form meant to be ingested. It's another gap that could be addressed. San Pellegrino water contains sulfur, which is why groups that like alkaline water hate that brand. You can't make sulfur water alkaline. If you have the funds, drinking that water is an option, but I don't know if it's sufficient to fill a gap.

Sulfate is not waste. It regulates dopamine, epinephrine, and norepinephrine through sulfation, maintains the gut's protective mucus lining, sulfates bile acids for fat digestion, and helps detoxify phenols. When sulfite is produced faster than SUOX can convert it, sulfite accumulates and sulfate falls: neurotransmitters linger, mast cells release more histamine, the gut barrier weakens, oxidative stress rises, and active B6 and thiamine get damaged. The autism literature consistently reports elevated urinary sulfite and reduced sulfate findings in autism.

I do want to note that the SUOX gene is not directly linked to autism, whereas numerous purine and aldehyde genetics are. However, there are genetics that cause sulfate wasting that have been found and studies on prenatal sulfur intake levels suggest that higher sulfur intake (via fancy bougie water) correlated with fewer symptoms in autistic children. Giving molybdenum improved sulfate levels in 1/3 of autistic children in one study. There are many gaps in the research with sulfur and sulfite which would answer a lot of questions on what we need for our health.

The exact issue with sulfites and autism is confusing. We lose significantly more sulfites than neurotypicals in our urine, that is known and studied; but it's not clear if we simply flush it through our kidneys or have neurotoxic levels in our tissue. That has never been clarified in research, and even if it was, I believe there are solid reasons to look at burnout independently for sulfite toxicity. I would LOVE for autistic catatonia to look at sulfite toxicity because I haven't found an answer to my question about sulfite levels there either. I looked. It's missing anywhere I could think of to check. Whether we flush it through our kidneys or retain toxic levels, both lead to a sulfate deficiency, which has been found in studies. I didn't know enough about sulfites to test at the time, but looking back, I do believe I had symptoms of high sulfites, including unexplained nausea and my mental health changing drastically. I see other neurodivergents talking about symptoms like consistent nausea without realizing that it may not be a fixed part of neurodivergence for all of us.

I want to be clear about why this isn't a footnote to the MoCo section. Whether we're sulfite toxic or sulfite wasting, either direction lands us at a sulfate deficiency, but sulfite itself is not a passive marker along the way. It has its own mental health implications, and it aggravates mast cells and the immune response directly. As the MoCo research gains ground, sulfite is the piece of that system I have the most unanswered questions about. Lipopolysaccharides, in studies, appear to drive more sulfite production, on top of whatever we're already struggling to convert to sulfate, and the ATP that LPS releases runs through the same purinergic danger-signaling pathway I described earlier in this site. Sulfite, LPS, and purines look like one interconnected feedback loop we risk getting stuck at.

The answer I found to lower sulfite levels: support the MoCo enzyme with supplements (in my case, the molybdenum deficiency was huge), reduce the preservatives I ate by eating whole food, and bind LPS.

3 sources

• How Sulfite Destroys Your Mental Health (Chris Masterjohn, Substack)
• Urinary Sulphate Excretion in Subjects with AutismFound markedly elevated urinary sulfite and reduced sulfate in autistic participants, suggesting altered sulfur metabolism and impaired sulfite oxidation.
• Sulphate Levels in Plasma and Urine in AutismFound significantly reduced plasma sulfate concentrations together with altered urinary sulfur metabolites, supporting impaired sulfur metabolism.

Tylenol debacle

When I say detoxify phenols, this is where the research seemed to stop and I wish it hadn't. This was studied in the 90s over several studies that were wondering how well a subgroup of autistic children handled phenols in foods (grapes, chocolate, etc. contain phenols). When the whole Tylenol debacle came out, I was immediately reminded of those studies because they used paracetamol, aka Tylenol, because it has the same phenol ring that the foods the children were reacting to had. What they found was that those children did not handle paracetamol in the body the correct way. They didn't have sufficient sulfur to handle Tylenol/paracetamol with the appropriate pathway, so their body relied on alternate pathways that are much harder on the body. In short, they didn't process Tylenol properly, and thus the studies concluded didn't handle foods with the same phenol amines properly.

Does Tylenol cause autism? Absolutely not. But Tylenol needs sulfur, and we're known to be sulfur deficient.

The studies back then speculated it was possibly an issue with the PST enzyme (now renamed SULT enzyme). It would be real helpful to know if this is only an issue in a subgroup or if all of us share this, because there are common pain killers that don't require sulfur, and this is where our general health would be impacted. When the people who did the study on Tylenol recently concluded that Tylenol could cause autism, they excluded all research that was not prenatal or natal. They never saw these studies done in the 90s. There are other studies that show that transsulfuration patterns are also present in the parents as well as the children.

Their methodology in the study was sound. The question they asked lacked even a basic knowledge of our metabolism.

It should not be a surprise that a drug requiring sulfur aggravates a population that is consistently found to have sulfur issues.

3 sources

• Biochemical Parameters in Autistic Children (1997)This study used paracetamol (acetaminophen) as a probe to measure sulfation capacity and found that autistic children had significantly lower plasma sulfate levels, reduced platelet phenol sulfotransferase (PST) activity, and excreted significantly less paracetamol as its sulfate metabolite, indicating a reduced ability to sulfate and metabolize phenols and phenolic amines.
• Sulphation Deficit in "Low-Functioning" Autistic Children: A Pilot Study (1999)This pilot study found that autistic children had a dramatically lower urinary paracetamol sulfate-to-glucuronide ratio than controls (p < 0.00002), providing evidence of impaired sulfation capacity and supporting the hypothesis that some autistic children have a reduced ability to metabolize phenols, phenolic amines, and other compounds that depend on sulfation for detoxification.
• Association of Cord Plasma Biomarkers of Acetaminophen Exposure With Risk of Attention-Deficit/Hyperactivity Disorder and Autism Spectrum Disorder (2019)This prospective birth cohort study measured acetaminophen metabolites in umbilical cord blood rather than relying on maternal recall. Children with the highest cord plasma acetaminophen biomarker levels had a significantly higher risk of later being diagnosed with ADHD or autism spectrum disorder compared with those in the lowest exposure group.

Aldehydes took the longest for me to appreciate. At first, I couldn't see what they had to do with the rest of the picture. The genetics back the importance. 7 of the 19 genes that handle aldehydes are connected to autism or speculated to be, and the same small MOCOS study that started me on this path found 3 of 11 participants with an AOX1 disruption independent of the MOCOS finding. So 8 of 11 had a MOCOS down regulation, 3 had AOX1 disruption, one overlapped, and one had none. 10 out of 11 was the final number for either a MOCOS or AOX1 disruption, which is incredibly unified for an autism study.

Aldehydes have the potential to be one of the bridges between chemical sensitivities and candida commonly found with autism. They also gave a potential reason for why I saw studies that seemed to be conflicting but maybe aren't. Early on, I remember seeing studies that claimed to fix autism with antifungals, a separate one saying that clostridia was probably a contributing issue, and then candida speculation was all over the place. None of these things seemed to have anything to do with the other, and my initial impression was that researchers were digging blindly. I couldn't figure out how any of it had to do with a genetic condition, and I wanted to dismiss it; but once seen, it could not be unseen, and with time, things made more sense.

It was confusing to see studies covering elements that seemed so unrelated until I asked if all of those produce aldehydes. It doesn't mean it's the whole picture, but I was trying to figure out how much weight to put on MoCo, and this pushed further into believing this enzyme was having an impact. Chemical sensitivities are a sensitivity to the aldehydes emitted from perfume, smoke, or cleaning products that can trigger neurological or respiratory responses such as migraines, nausea, and asthma. If we have a down regulation of what is needed to handle aldehydes, anything producing them in our body or externally is going to be a problem because we won't be able to process them as well. If we have deficiencies further encumbering the enzyme that's already down regulated, we're going to have even more problems. It's like trying to push too much paper through a paper shredder. Pushing harder does nothing. If you add nutrient deficiencies on top of that, you might as well be removing teeth from the shredding mechanism. The paper comes through whole instead of shredded and sticks around to be shredded again by a machine that is already back logged and struggling.

3 sources

• The Pivotal Role of Aldehyde Toxicity in Autism Spectrum Disorder: The Therapeutic Potential of Micronutrient SupplementationThis hypothesis paper proposes aldehyde toxicity as a unifying mechanism contributing to many features of autism. It reviews evidence linking aldehydes to oxidative stress, micronutrient depletion, protein damage, DNA damage, and impaired mitochondrial function.
• Rapid Complete Recovery From an Autism Spectrum Disorder After Treatment of Aspergillus With Antifungal DrugsCase report describing marked improvement following treatment of Aspergillus infection. The authors propose fungal metabolites, including aldehydes, as one possible contributor deserving further study.
• Gastrointestinal Microflora Studies in Late-Onset AutismThis study compared the intestinal bacteria of children with regressive autism and healthy controls and found significantly higher numbers and diversity of Clostridium species in the autistic group. Children with autism harbored nine Clostridium species not found in controls, while controls had only three species absent from the autism group. The authors proposed that abnormal colonization by toxin-producing clostridia may contribute to symptoms in a subset of autistic children and highlighted the gut microbiome as a potential therapeutic target.

What aldehydes are and how they damage

Aldehydes bind rather than float past. They form irreversible adducts with proteins, inactivating them, and with DNA, causing strand breaks and mutations. The AOX1 enzyme (part of MoCo) helps clear them. One hypothesis paper on aldehydes made the strong claim that the many symptoms and divergent theories of autism are consistent with aldehyde toxicity, and laid out four ways they damage us: micronutrient depletion, oxidative stress, protein inactivation, and DNA damage. Whether they explain all of autism or not wasn't my concern. I looked at them like another burden to make sure I wasn't adding to my system any more than necessary.

Where they come from

• Outside the body: vehicle exhaust, smoke, cooking fumes, browned and fried food (especially reused oil, like fast food), off-gassing from furniture, carpet, and cosmetics, and many foods and natural flavorings such as vanilla, cinnamon, and citrus. Indoor levels run four to ten times outdoor. Alcohol and smoking produce them too. But this wasn't my biggest concern because the studies suggest that the larger problem might be internal production, or at least that was my read of it. All the same, I don't want to work at a factory breathing in paint fumes all day. I stopped eating fried food pretty immediately, was careful to not burn my food, and simplified my cosmetics. I eventually was able to quit smoking weed altogether and alcohol as a weekly habit. I quit marijuana altogether, but edibles may not provide aldehydes the way smoking does. I haven't looked into this yet.
• Inside the body: reactive oxygen species hitting fats, called lipid peroxidation, throws off more than 200 different reactive aldehydes such as 4-HNE, 4-HHE, and MDA. ROS are unstable oxygen molecules from normal metabolism. In small amounts, antioxidants handle them, but when they outpace defenses you get a burden that contributes to oxidative stress, one of the most consistently replicated findings in autism.
• The gut: yeast and bacteria, Candida especially, generate them directly. Candida thrive on purines, but they offput aldehydes as a part of them living in our body. I did address candida in my gut.

What aldehydes impact

They consume the body's defenses as they go, depleting sulfur antioxidants (glutathione, cysteine, taurine) and locking up B1, B6, folate, zinc, and magnesium, and they strip zinc out of proteins, including the very enzymes meant to clear aldehydes and ROS. The lipid-peroxidation ones travel across membranes and damage neighboring cells far from where they formed.

How much weight I gave it, and why

Because the study was so small, I went on side quests to see whether the markers of each MoCo enzyme's dysfunction showed up in autism independently. They did, enough to satisfy me, at least. Then I compared with the wider literature and theories on autism. MoCo had its toe in numerous areas. Those side quests are in the appendix. There are numerous paths to Rome (autism), MoCo seems involved in a portion of the journey.

Burnout makes more sense to me now that I know we are a population whose most common metabolic snag sits on its energy pathways.

Demand up, capacity down

This is part of why burnout is hard to climb out of: the elements it produces in your body become what spirals you further. The HPA axis, the body's central stress system, directly compromises the gut barrier when it is chronically active. Cortisol loosens the tight junctions, the wall turns permeable, and LPS gets into the blood. That aggravates the HPA axis, which makes more cortisol, which opens the gut further, which lets in more LPS. Addressing LPS felt like interrupting a loop that stress had created and LPS was sustaining, if not spiraling me further. I was not lowering inflammation in general. I was lowering the inflammation specific to what is found in autism.

MOCOS/MoCo are important because LPS doesn't just activate the immune system. It increases the metabolic work the body has to perform. LPS increases oxidative stress and stimulates nitric oxide production. In small amounts, nitric oxide is beneficial, helping regulate blood flow and support immune defense. During chronic inflammation, however, excess nitric oxide reacts with superoxide to form peroxynitrite, which damages mitochondria and oxidizes BH4. At the same time, LPS causes cells to release ATP as a danger signal, activating purinergic signaling. That ATP is eventually broken down through the purine degradation pathway, increasing demand on xanthine dehydrogenase, one of the body's molybdenum cofactor (MoCo)-dependent enzymes. LPS also promotes lipid peroxidation, generating reactive aldehydes that must be detoxified by aldehyde-metabolizing enzymes. Those are both the pathways a down regulation was found in. In other words, one trigger is increasing the workload across several pathways that struggle in a way unique to autism.

Rest lowers demand. It doesn't repair capacity.

Removing a burden isn't fringe medicine

Dialysis removes what the kidneys can't clear. Chelation removes heavy metals. Reducing what a struggling clearance system has to process, while supporting the system, is standard practice.

It hasn't been looked at through this lens for autism, where the clearance system is a set of enzymes under a heavier load than they were built for, not an organ. The sign of this burden that needs to be removed is the low glutathione findings that are common. I think findings in the brain are interesting, but my brain was never my problem. My nervous system was, and this addressed my nervous system.

Instead of forcing the kitchen to work harder, I stopped overwhelming it and gave it resources to catch up. When you ask a different question, you find a different solution.

What I changed to heal

Binders: what I did and didn't do

One of the larger disruptions to my decline was binding LPS specifically. I don't agree with taking generic binders. I agree with testing for any heavy metals, but those often have specific chelation therapy that can be supervised by a doctor. I used chitosan oligosaccharide once I knew I wasn't nutrient deficient. Activated charcoal is an option for vegans and vegetarians. Binders can also bind nutrients, and should be taken with that in mind and away from food and medicine. I took a mineral supplement while taking it, for peace of mind. I don't agree with heavy herb detoxes that risk reducing gut bacteria further or nonspecific binders like zeolite. Gut testing lets you know what food/probiotic support will add diversity.

Removing toxins is not fringe medicine. Dialysis removes toxins, as an example. It removes what the kidneys can't clear so the rest of the body can keep working around the gap. Chelation for heavy metals runs on the same logic. Reducing what a struggling clearance system has to process, while supporting the system itself, is a part of medicine.

Nobody has applied that lens to autism. We have a finding, low glutathione, repeated across dozens of studies, and the response is to suggest taking glutathione. The answer to what is consuming it is inconsistent if you look at heavy metals. The question gets skipped outside of that because the field is organized around finding a cure, and a cure means one thing. I'm not convinced that a single gene exists in the way the search assumes, given how many subgroups we're split into. Even in MoCo, one participant had none and two had aldehyde only. In the meantime, people are living in bodies that need help now.

So my answer for my own quality of life became this: treat it as demand against capacity. Reduce what my body has to clear, support the systems doing the clearing, regulate to protect myself from further deterioration. I've seen burnout have irreparable consequences, both growing up and as an adult, and I was not willing to risk hoping a solution would be found.

Feeding diversity, not just "good bacteria"

Stressed and take probiotics? I found they helped if I took them after a stressful event more than just taking them every morning.

2 sources

• Prebiotic mechanisms of resistant starches from dietary beans and pulses on gut microbiome and metabolic health in a humanized murine model of aging
• Prebiotic Structural Diversity Shapes Gut Microbial Diversity, Community Composition, and Metabolic Activity In Vitro

When you have energy, life is less stressful

Why this is the other half

Everything I talk about implementing sounds like it would make life harder. Life is now easier. Even the hard times are less depleting because I have the reserves.

Exercise for regulation

Breathing exercises for regulation

What filling your cup ended up meaning to me

Connection: why regulation is vital in interacting with people

Purine pathway (recycling and de novo synthesis): folate (two separate steps in building new purines), glycine, glutamine, and aspartate (raw materials for the new-purine assembly line), PRPP, and ATP itself to fund the process. The enzyme that finishes purine breakdown into uric acid, xanthine dehydrogenase, is a molybdo-flavoenzyme, meaning it needs both MoCo (molybdenum) and FAD (B2), plus iron, to function at all. Purines touch nearly every nutrient on this page in one direction or another.

MoCo (the molybdenum cofactor system): molybdenum itself, copper, iron (as iron-sulfur clusters), SAMe (the enzyme that starts MoCo synthesis is a radical-SAMe enzyme), zinc, magnesium, L-cysteine, and P5P (active B6), which two of the MoCo-building enzymes require directly. This is a longer dependency list than I expected when I first found the MOCOS study, and it's part of why I don't think of MoCo support as "take molybdenum" alone.

1 source

• Molybdenum Cofactor (Research Notes by Sergey)

Glutathione: glutamine, cysteine, and glycine as the three building blocks, plus B6, B2, and selenium to run the enzymes that assemble and recycle it.

B2 (riboflavin), and why it matters for energy specifically: as FAD and FMN, B2 is the required cofactor for Complex I and Complex II of the electron transport chain, which is where ATP is actually generated. It's also required for glutathione reductase, the enzyme that regenerates active glutathione from its spent form, for MTHFR in the folate cycle, and for xanthine dehydrogenase in the purine pathway alongside MoCo. B2 sits at the intersection of energy production, antioxidant recycling, and purine handling, so a shortfall here doesn't hit one system, it touches all three at once.

B6 (as P5P, the active form), and why it's needed: P5P is the cofactor for CBS, the enzyme that runs transsulfuration toward cysteine and glutathione, for the transaminase enzymes (GOT1/GOT2) that were shown suppressed in the LPS paper, for the decarboxylase enzymes that build dopamine, serotonin, and GABA, and, per the MoCo dependency list above, for MOCOS and NFS1, the two enzymes that sulfurate MoCo itself. B6 shows up in nearly every pathway described on this site.

Zinc: IAP at the gut wall, riboflavin kinase (B2 activation), the MoCo system, many antioxidant and metabolic enzymes. Depleted by LPS; the IAP loop is the trap. Don't take with iron and don't take if you're anemic without supporting iron. You'll deplete your iron further.

Magnesium: FAD synthetase (B2 activation), ATP-related processes, many enzymes. Chronic stress increases demand and loss.

Balancing homocysteine: two ways back, and both are already covered here. Remethylation back to methionine needs folate (as methylfolate) and B12 through methionine synthase, or betaine as a backup route through BHMT. Transsulfuration toward cysteine and glutathione needs B6-dependent CBS.

MCT oil, worth trying for energy specifically: this one is a tool rather than a nutrient requirement. MCT oil (medium-chain triglycerides) skips the carnitine shuttle that ordinary long-chain fats need to enter the mitochondria, so it converts to usable ketone energy faster and more directly. If the ATP/purine system described throughout this site is already strained, MCT oil offers an energy route that doesn't have to pass through as many of the strained steps to become usable fuel. It's not a fix for the underlying pathways, just a more direct fuel source while those pathways are being supported.

1 source

• An impaired glycolysis induces ATP deficiency and reduced cell respiration in stem cells of patients with autism spectrum disorders (Féron et al. 2025)Source for disrupted carnitine biosynthesis across the cohort (low α-ketoglutarate and ascorbic acid), and reviews the prior serum carnitine, TMLHE, and supplementation-trial findings.

Sulfites

Pyridoxal kinase. Sulfite doesn't inhibit this enzyme directly, but it reduces the available pool of PLP (active B6) it depends on, which can indirectly slow the conversion of PL to PLP.

1 source

• Abnormally high plasma levels of vitamin B6 in children with autism not taking supplements compared to controls not taking supplements

Glutamate dehydrogenase (GDH). Sulfite binds and inhibits GDH activity in a dose-dependent manner, meaning the more sulfite present, the more this enzyme is suppressed. Suppression of GDH certainly wouldn't be helping our glutamate excitotoxicity.

2 sources

• A mechanism of sulfite neurotoxicity: Direct inhibition of glutamate dehydrogenase
• The role of glutamate and its receptors in autism and the use of glutamate receptor antagonists in treatment

Pyruvate dehydrogenase complex (PDH) and α-ketoglutarate dehydrogenase (KGDH). Sulfite doesn't bind these directly, but both require thiamine pyrophosphate (active B1) as a cofactor, and sulfite destroys thiamine by cleaving its methylene bridge. Losing the cofactor supply shuts these enzymes down just as effectively as a direct block would.

3 sources

• Sulfites inhibit the growth of four species of beneficial gut bacteria at concentrations regarded as safe for food (PLOS One)
• Dysautonomia in Autism Spectrum Disorder: Case Reports of a Family with Review of the Literature
• Alterations in mitochondrial DNA copy number and the activities of electron transport chain complexes and pyruvate dehydrogenase in the frontal cortex from subjects with autism (Translational Psychiatry)

Enzymes with a critical disulfide bond or cysteine residue. Any enzyme that depends on a disulfide bond or an oxidized cysteine to function is vulnerable to sulfite directly breaking that bond. Two examples follow.

Thyroid peroxidase (TPO). Synthesizes thyroid hormone and depends on multiple disulfide bonds for its structure and proper cellular localization.

1 source

• Maternal thyroid autoantibody and elevated risk of autism in a national birth cohort

Protein disulfide isomerase (PDI). Sits in the endoplasmic reticulum and catalyzes the formation, isomerization, and reduction of disulfide bonds in new polypeptides, which is how proteins get folded correctly in the first place.

1 source

• The de novo autism spectrum disorder RELN R2290C mutation reduces Reelin secretion and increases protein disulfide isomerase expression

Thioredoxin reductase (TrxR). Regenerates thioredoxin, a small protein central to keeping the cell's redox balance in check. Disrupted thioredoxin/TrxR signaling has specifically been found in autistic neutrophils.

1 source

• Thioredoxin 1 and Thioredoxin Reductase 1 Redox System Is Dysregulated in Neutrophils of Subjects with Autism: In Vitro Effects of Environmental Toxicant, Methylmercury

CYP1A2. A liver enzyme involved in drug and toxin metabolism. In a rat model of sulfite oxidase deficiency, meaning excess sulfite exposure, hepatic CYP1A2-dependent activity dropped by roughly 28% against controls.

1 source

• Alteration of drug metabolizing enzymes in sulphite oxidase deficiency

Aldehydes

Reactive aldehydes, whether internally produced (acetaldehyde from normal metabolism, 4-HNE from lipid peroxidation) or from outside sources (acrolein, formaldehyde), damage proteins by forming permanent bonds at specific amino acid sites: Schiff base adducts at lysine or arginine, or Michael addition products at cysteine or histidine. When those sites sit in an enzyme's active center, the enzyme stops working.

Dopamine β-hydroxylase (DBH). Certain aromatic aldehydes act as mechanism-based inhibitors of DBH, the enzyme that converts dopamine to norepinephrine. Increased norepinephrine alongside decreased DBH activity has been specifically documented in primary autism.

2 sources

• Mechanism-based inhibition of dopamine beta-monooxygenase by aldehydes and amides
• Increased Norepinephrine Levels and Decreased Dopamine-β-Hydroxylase Activity in Primary Autism (JAMA Psychiatry)

Glucose-6-phosphate dehydrogenase (G6PD). The rate-limiting enzyme of the pentose phosphate pathway, which produces NADPH for antioxidant regeneration. Acetaldehyde blocks its catalytic activity directly. G6PD deficiency itself has also been studied for a possible association with autism.

2 sources

• Covalent binding of acetaldehyde selectively inhibits the catalytic activity of lysine-dependent enzymes
• Role of glucose 6-phosphate dehydrogenase (G6PD) deficiency and its association to Autism Spectrum Disorders

Pancreatic ribonuclease (RNase A). A digestive enzyme that depends on lysine for catalysis. Acetaldehyde selectively inactivates lysine-dependent enzymes like this one.

2 sources

• Covalent binding of acetaldehyde selectively inhibits the catalytic activity of lysine-dependent enzymes
• Pancreatic Replacement Therapy for Maladaptive Behaviors in Preschool Children With Autism Spectrum Disorder

Angiotensin-converting enzyme (ACE). Critical for blood pressure regulation. Acetaldehyde rapidly and directly inhibits ACE activity. Genetic variants of ACE have separately been linked to autism.

2 sources

• Acetaldehyde inhibits angiotensin-converting enzyme activity of bovine lung
• Genetic Variants of Angiotensin-Converting Enzyme Are Linked to Autism: A Case-Control Study (PLOS One)

Glutathione reductase (GR). The enzyme that regenerates active glutathione from its spent, oxidized form. 4-HNE and acrolein irreversibly inactivate GR by attacking cysteine and histidine residues at its active site, first forming a reversible complex and then a permanent one. Acrolein, crotonaldehyde, and cinnamaldehyde inactivate it through related mechanisms at different rates, and methylglyoxal does it by modifying arginine residues instead. Over time, these adducts can cross-link GR's subunits together.

2 sources

• Inactivation of glutathione reductase by 4-hydroxynonenal and other endogenous aldehydes
• The impact of glutathione metabolism in autism spectrum disorder

Arylamine N-acetyltransferase 1 (NAT1). Handles phase II detoxification of aromatic amines. Acrolein irreversibly inhibits it. The gene is separately linked to autism.

2 sources

• Acrolein, an α,β-unsaturated aldehyde, irreversibly inhibits the acetylation of aromatic amine xenobiotics by human arylamine N-acetyltransferase 1
• NAT1 peptide alpha-N-acetyltransferase complex A subunit NAT1 (NCBI Gene)

Aspartate aminotransferase (AST, cytosolic). A B6-dependent (PLP) enzyme that transfers amino groups between aspartate and α-ketoglutarate. Acrolein modifies and inhibits it directly.

2 sources

• Acrolein modifies and inhibits cytosolic aspartate aminotransferase
• Developmental Regression and Mitochondrial Dysfunction in a Child With Autism

PDH and KGDH, through a second route. I already mentioned these two under sulfites, because they need thiamine. They're also vulnerable to aldehydes through a completely separate mechanism: both have an E2 subunit carrying a lipoic acid cofactor, which is itself a cyclic disulfide, and 4-HNE and acrolein preferentially attack the reduced, active form of it. Humphries and Szweda showed this causes near-complete inactivation of both PDH and KGDH while sparing other TCA cycle enzymes, meaning aldehydes hit this specific point in mitochondrial energy production especially hard.

2 sources

• Humphries & Szweda (1998), selective inactivation of α-ketoglutarate dehydrogenase and pyruvate dehydrogenase by 4-hydroxy-2-nonenal
• Mitochondrial Dysfunction in Autism (JAMA)

Purines

Purine toxicity works differently from sulfites and aldehydes. Purine metabolites are normal cellular molecules, not foreign compounds, so "toxicity" here means the normal molecule building up past the level the body can handle.

2 sources

• Purine signaling pathway dysfunction in autism spectrum disorders: Evidence from multiple omics data
• Metabolic treatment of hyperuricosuric autism

Ribonucleotide reductase (RNR). Converts ribonucleotides into the deoxyribonucleotides needed for DNA replication, and is allosterically shut down by high levels of certain purine breakdown products. In purine nucleoside phosphorylase (PNP) deficiency specifically, accumulated deoxyguanosine converts to dGTP, which inhibits RNR, hitting T-cells especially hard.

1 source

• Adenosine deaminase impairment and ribonucleotide reductase activity and levels in HeLa cells

S-adenosylhomocysteine hydrolase (AdoHcy hydrolase). The enzyme that irreversibly breaks SAH down into adenosine and homocysteine, which is what drives the whole methylation cycle forward. High intracellular adenosine or deoxyadenosine locks this enzyme in an adenosine-bound state, effectively shutting it down, meaning a purine buildup can jam the methylation cycle at this specific step.

1 source

• Metabolic biomarkers of increased oxidative stress and impaired methylation capacity in children with autism (James et al. 2004)

BH4

Oxidative stress oxidizes BH4 to BH2, uncoupling the four BH4-dependent conversions (dopamine, serotonin, melatonin) and flipping nitric oxide synthase into a superoxide source. BH4 comes from GTP in the purine de novo pathway, so purine disruption hits it from one side and oxidative stress from the other. LPS adds a third route through peroxynitrite. MoCo disruption increases oxidative stress through the xanthine pathway.

Microglia

Microglial activation runs on purinergic signaling and produces oxidative and aldehyde load, the same currencies the MoCo enzymes handle.

Excitatory / inhibitory imbalance

Two routes converge: SUOX-limited sulfite forms S-sulfocysteine, an NMDA agonist driving excitotoxicity and calpain-mediated gephyrin destruction; and PLP shortage slows glutamate-to-GABA conversion (that enzyme is B6 dependent). Gephyrin is where the MoCo build and inhibitory-synapse scaffolding meet.

Mast cells, MCAS, and POTS

Sulfite triggers non-IgE degranulation through NADPH-oxidase ROS. LPS has its own TLR4 route. Enzymes at the intersection: DBH (aldehyde-inhibited, copper-dependent); renin (acetaldehyde triggers mast-cell release); tryptase (sulfite and oxalate both trigger); COX-2 (sulfite-driven prostaglandin release). MCAS/POTS is a possible downstream manifestation, not the organizing principle.

5 sources

• Mast cell degranulation and renin release induced by acetaldehyde
• Effect of sodium sulfite on mast cell degranulation and oxidant stress
• Mechanism of ketotifen fumarate inhibiting renal calcium oxalate stone formation in SD rats
• Adverse reactions to the sulphite additives
• Roles of Prostaglandins and Cyclooxygenases in Autism Spectrum Disorder: A Comprehensive Review

Essential fatty acids

Membrane PUFAs are vulnerable to lipid peroxidation, producing reactive aldehydes. Reduced AOX1 may increase aldehyde persistence, linking membrane integrity indirectly to MoCo-dependent aldehyde metabolism.

PANS, PANDAS, and post-viral

Infection loads all three MoCo queues at once: xanthine oxidase is upregulated in inflammation, immune cell turnover pushes ATP out, immune cells responding to endotoxin generate sulfite. A system at its clearance ceiling has no reserve for the surge. The overlap is capacity, not cause; this framework does not explain the antibody mechanisms. It may explain why some of us flare harder and recover slower.

Candida

Produces acetaldehyde directly through ethanol metabolism, upstream of AOX1. Also arabinose (lysine adducts). The loop: purines feed candida, stress raises purine turnover, candida raises aldehyde load, aldehyde load competes for the same sulfurated cofactor that clears purines.

Clostridia

Loads two queues: acetaldehyde and related aldehydes into AOX1; phenolic metabolites (p-cresol, HPHPA) that consume sulfate, the pool SUOX is already failing to replenish. Competes for the sulfation capacity measured in the 90s paracetamol studies, so the phenol findings and the clostridia findings may be one finding from two angles.

Glyphosate and PIN1

Seneff's glyphosate work has received substantial criticism. One component of her mechanism involves PIN1, which regulates gephyrin at inhibitory synapses; gephyrin also completes MoCo biosynthesis. Whether PIN1 regulates gephyrin's MoCo function has not been investigated. Known links exist; the proposed connection is untested. Not a cause of MOCOS downregulation; possibly a mimic of one side of it.

7 sources

• Metabolic biomarkers of increased oxidative stress and impaired methylation capacity in children with autism (James et al. 2004)
• Plasma Cytokine Profiles in Subjects with High-Functioning Autism Spectrum Disorders (2011)
• Neuroglial activation and neuroinflammation in the brain of patients with autism (Vargas et al. 2005)
• S-sulfocysteine/NMDA receptor-dependent signaling underlies neurodegeneration in molybdenum cofactor deficiency (Kumar et al. 2017)
• Effect of sodium sulfite on mast cell degranulation and oxidant stress (Collaco et al. 2006)
• Autistic Children Exhibit Decreased Levels of Essential Fatty Acids in Red Blood Cells (2015)
• Is autism a PIN1 deficiency syndrome? A proposed etiological role for glyphosate

A personal note: how did a genetic autoimmune clear up?

I got diagnosed in 2013 with a genetic autoimmune called Congenital Adrenal Hyperplasia, partial 3β-HSD diagnosis via ACTH stimulation test. An unexpected result of this work was that bloodwork improved yearly since addressing nutrition until it normalized. The endocrinologist ran a renin test, questioning if the CAH diagnosis was wrong, which came back normal. No CAH genetics have been found on testing. I'm questioning if enzyme function can be impaired by more than one mechanism and have the result look the same. The CAH-family enzymes each have a documented toxin-driven vulnerability separate from the genetic story: CYP21A2; CYP1A2 (sulfite, above); CYP11B1 (blunted ACTH response in hyperuricemia); CYP17A1 (lipid peroxidation drops activity to ~13% within minutes); HSD3B2 (downregulated alongside CYP11B1 in hyperuricemic mice); StAR (acrolein exposure suppresses it).

5 sources

• Androgen levels in autism spectrum disorders: a systematic review and meta-analysis
• Frontiers: Pseudohypoadrenalism, a subclinical cortisol metabolism disorder in hyperuricemia
• Relative inactivation of steroidogenic enzyme activities of in vitro vitamin E-depleted human adrenal microsomes by lipid peroxidation
• Effects of maternal acrolein exposure during pregnancy on testicular testosterone production in fetal rats
• Cholesterol metabolism pathway in autism spectrum disorder: From animal models to clinical observations