Organic Acids Test

What Is the Organic Acids Test?

The Organic Acids Test (OAT) is a urine test that measures over 70 organic acids that can provide insights into a body’s metabolic function, nutritional deficiencies, gut microbiome health, mold exposure, neurotransmitter activity, and detoxification pathways. It is commonly used by functional-medicine practitioners to check for metabolites (biomarkers, or downstream cellular by-products of enzymatic cellular pathways) that can contribute to a range of symptoms within the bodyand health conditions.

For example, malic acid, a common molecule needed by the body to make energy (and incidentally the acid that gives apples their sour taste), could be converted by fungus/ yeast in the gut into the rare organic acid citramalic acid. Humans are supposed to have malic acid in their systems, but little if any citramalic acid should be present (or yeast for that matter). The Organic Acids Test can be used to determine if citramalic acid is present in urine beyond normal levels. The urine of a child diagnosed with ADHD or autism, for example, could have from three to ten times the normal level of citramalic acid. The Organic Acids Test can be used in this case to determine if citramalic acid is present in urine beyond normal levels.

Problematic organic acids are confusing to the body because they are so similar (or analogs) to other molecules that are naturally used by our bodies tto create energy. When too high, the body is “tricked” into substituting these analogs for the ones we need. Problems ensue when the biochemical reaction attempts to run with a substitute substance that is not exactly right. Biochemists often compare this situation to using the wrong key in a lock. The key may slip in easily, but not turn properly, or break off, or even ruining the lock for future render the lock completely useless. Furthermore, when a lot of problematic acids accumulate in the body, the acid itself can cause harm.

Symptoms That Can Be Corroborated with an Organic Acids Test

Symptoms occur when the level of these organic acids becomes so high that the body cannot process all their toxic waste and it “spills over“ into the blood. When the blood is filtered by the kidneys, these metabolites can be quantified and analyzed from a urine sample. The symptoms of overabundance of certain metabolites in the body are wide-ranging and vary in severity depending on the quantity and type of metabolite. Symptoms can include:

• Sleep disturbances
• Perseverative behaviors
• Failure to thrive
• Symptoms of neurodevelopmental disorders such as autism and ADHD
• Seizures
• Gastrointestinal symptoms

Measuring metabolite levels in the urine with an OAT can help a root cause-oriented practitioner investigate a particular diagnosis, explore what type of treatment might be warranted, and document change or effectiveness of a treatment with repeat testing. They can also compare the results to different biomarkers (e.g., genomic variants that influence detoxification or inflammatory pathways or neurotransmitter production, or the microbiome of the gut, or blood or other tissue sample analysis that measures toxins like heavy metals or essential vitamins and minerals). Testing should help improve the probability of achieving quality health care.

For Which Health Conditions Might an Organic Acids Test Be Helpful?

The OAT’s unique perspective on cellular metabolism makes it exceptionally useful for a broad spectrum of health conditions. Some key areas or diagnoses include:

Autism

Diagnoses such as autism spectrum disorder can be supported by measuring markers linked to underlying probelms of  mitochondrial dysfunction, metabolic dysfunction, gut dysbiosis and more. For example, this study used gas chromatography-mass spectrometry and machine learning to identify 20 key urine organic acids as potential biomarkers for autism in Chinese children, achieving 93% accuracy in distinguishing autism from typically developing children. Among these key organic acids that can be measured with an OAT are:

• Oxalic acid
• Tartaric acid
• Pyruvic acid
• 4-Cresol
• Carboxycitric acid
• 3-hydroxyglutaric acid
• 2-hydroxybutyric acid
• 2-oxoglutaric acid

Another study showed that the OAT can assess biochemical and nutritional individuality in children with autism. Levels of the organic acids 2-oxoglutaric acid, citric acid, 4-hydroxybenzoic acid, 4-hydroxyphenylacetic acid, hippuric acid, adipic acid and suberic acid were all found to be significantly different in children with autism versus the control group. All of these organic acids can be measured with the OAT. Isocitric acid is another organic acid described in this study that can be used as a biomarker, but it is not measured with the OAT.

HPHPA (3-(3-hydroxyphenyl)-3-hydroxypropionic acid) is another organic acid biomarker that is increasingly recognized for its clinical relevance in autism spectrum disorder. (See Sources & References, below, for relevant medical literature.) Elevated HPHPA levels are strongly associated with overgrowth of specific Clostridia bacteria in the gastrointestinal tract, including species such as C. sporogenes, C. caloritolerans, and C. botulinum. The HPHPA metabolite inhibits an enzyme that is responsible for converting dopamine to norepinephrine, leading to dopamine accumulation and reduced norepinephrine levels. This neurotransmitter imbalance is linked to core behavioral symptoms in autism such as aggressive behavior, self-injury, irritability, and obsessive-compulsive behaviors. Research indicates that combining HPHPA with other Clostridia markers—such as 4-cresol, 3-hydroxyphenylacetic acid (3HPA), and 3-hydroxyhippuric acid (3HHA)—can diagnose autism with 98.4% specificity. The severity of autism symptoms is directly correlated with the concentration of these markers. The organic acid 4-cresol is measured in an OAT while 3HPA and 3HHA are not.

Mood Disorders

The OAT can be helpful with diagnoses including depression, anxiety, and other psychiatric conditions, due to its evaluation of neurotransmitter metabolites. For example, 5-HIAA (5-hydroxyindoleacetic acid) is an organic acid that is a key metabolite of serotonin. It can be measured with an OAT to assess serotonin turnover and overall neurotransmitter balance. Abnormal (too high or too low) levels of 5-HIAA can indicate issues with serotonin production, metabolism, or related pathways, and these issues are often associated with conditions such as mood disorders, sleep disturbances, and gastrointestinal issues. In addition, a study found a relationship between generalized anxiety symptoms and urinary levels of 5-HIAA and vanillylmandelic acid (VMA), both of which can be measured by OAT to support an anxiety diagnosis and to better address underlying root causes.

Autoimmune Disorders

A study using gas chromatography-mass spectrometry identified statistically significant differences in the organic acids succinate, methylcitrate, malate, pyroglutamate, 2-hydroxybutyrate, methylmalonate, 4-hydroxyphenylpyruvate, 2-hydroxyglutarate and 2-hydroxyisobutyrate between subjects with an autoimmune disorder and the control group. In fact, these biomarkers have a high predictive accuracy of between 67% and 75% for an autoimmune disorder. Thus, the OAT could be a tool used for early diagnosis of an autoimmune disorder. These biomarkers are involved in energy production, metabolism, and /or detoxification, and when abnormal could indicate a variety of such conditions.

Mitochondrial Dysfunction

The diagnosis of mitochondrial dysfunction can be supported with the use of the OAT to measure levels of organic acid metabolites that are byproducts of energy production. Nearly every cell in the body (except red blood cells) requires the presence of mitochondria for energy production. This amounts to trillions of these “ancient-bacteria” in our bodies – the higher the energy demands of a tissue, the higher the number of functioning mitochondria required.

This study showed that abnormal levels of succinic acid, fumaric acid, malic acid, and lactic acid in the urine reflect disruptions in the citric acid (or Kreb’s) cycle and oxidative phosphorylation – two of the four major metabolic pathways that involve mitochondria). Another study found that urinary organic acids are clinically useful in diagnosing mitochondrial respiratory chain disorders in pediatric patients. It highlights elevated levels of organic acids such as methylmalonic acid, ethylmalonic acid, and 3-methylglutaconic acid, all measured by the OAT, as indicators of mitochondrial dysfunction.

Diabetes, Obesity and Metabolic Syndrome

The OAT can assess energy usage, blood-sugar handling, and nutrient status by measuring specific metabolites such as 3-hydroxybutyric acid and 2-hydroxybutyric acid, which are organic acids that can offer valuable insights into metabolic health and disease progression in diabetes. For example, 3-hydroxybutyric acid is an organic acid that is a key marker linked to diabetes. Elevated levels in urine are associated with impaired glucose utilization during fasting or in diabetic states, serving as a reliable indicator of insulin resistance and diabetes complications. Additionally, 2-hydroxybutyric acid has been investigated as a potential early biomarker for insulin resistance and glucose intolerance in non-diabetic individuals. See Sources & References, below, for medical literature.

Digestive Disorders

The OAT can help identify microbial imbalances, nutritional deficiencies, and oxalate production associated with gut dysfunction. For example, infection with the gram-positive bacterium, Clostridium difficile (C. diff) — now officially named Clostridioides difficile, is strongly associated with gastrointestinal disorders, primarily through its role in causing antibiotic-associated diarrhea and colitis. Its metabolite paracresol can be measured with the OAT. Another study demonstrated that elevated levels of 4-hydroxyphenylacetic acid in urine can serve as a screening marker for small-bowel disease; this metabolite can be measured with an OAT.

Mold Exposure

The OAT can evaluate both the presence of metabolic byproducts resulting from toxic and environmental exposures as well as the body’s detoxification capacity. For example, 5-hydroxymethyl-2-furoic acid (HMFA), furan-2,5-dicarboxylic acid, and furancarbonylglycine are organic acids that are byproducts of Aspergillus mold that can be detected by the Organic Acids Test.

Root Causes That Can Be Identified by an Organic Acids Test

One of OAT’s greatest strengths is pinpointing root causes of chronic health conditions rather than simply labeling symptoms.

Microbial Overgrowth

The OAT can detect metabolic byproducts from bacteria and fungi that humans do not produce, such as yeast and mold markers, Clostridia metabolites, and oxalates. Elevated levels can indicate overgrowth, even when gastrointestinal symptoms aren’t prominent. For example, yeast markers can explain bloating, diarrhea, brain fog, and even pain issues if oxalates are involved. In addition, Clostridia metabolites (e.g., HPHPA) disrupt dopamine conversion, leading to mood and focus issues—the “wired but tired” feeling.

Nutritional Deficiencies

OAT provides both direct and indirect markers for nutrients such as B vitamins, vitamin C, biotin, CoQ10, and more. Sometimes, through pattern recognition, practitioners can infer deficiencies (e.g., multiple elevations in pathways that require B1 may imply thiamine insufficiency). Early detection is important, as deficiencies often precede physical symptoms. OAT can help tailor supplementation and dietary guidance, ensuring precise correction of imbalances.

Neurotransmitter Imbalances

OAT measures end products and intermediates of neurotransmitters, including dopamine, norepinephrine, epinephrine, and serotonin. This provides clues such as those about enzyme function (e.g., COMT, MAO) as well as potential pathway blockages (e.g., Clostridia-inhibiting dopamine conversion). Such information connects symptoms such as depression, fatigue, or brain fog to underlying biochemical pathways.

Mitochondrial Dysfunction

Mitochondrial health is central to energy production and vitality. The OAT can be helpful in identifying clues to mitochondrial dysfunction such as the uses of amino acids, fatty acids, and glucose, as well as Krebs cycle intermediates such as succinic acid which can point to ATP synthesis issues when elevated.

Toxin Identification

The OAT can reveal some markers of toxic exposure, both directly (measuring metabolites resulting from toxin degradation) and indirectly (effects on metabolic enzymes). These may be particularly useful when there are known or suspected exposures or signs of liver compromise (e.g., elevated liver enzymes in routine blood work). For example:

• Succinic acid elevation can potentially flag the impact of environmental toxicants on ATP synthesis.
• Methylhippuric acid (2-methylhippurate) is sometimes used as a marker of xylene exposure (from substances like paint thinner, fuel, industrial solvents and building materials).
• Mycotoxin metabolites can be measured for mold exposure clues (as above).
• High glutaric acid can indicate a liver’s challenge with eliminating toxins such as pesticides, herbicides, solvents and petrochemicals as well as some medications.

This information allows for targeted detoxification protocols as well as further environmental investigation into toxicant sources.

Detoxification

Glutathione is a major supporter of the body’s detoxification systems. Its status reflects the body’s detox capacity. The OAT can assess biochemical pathways involved in methylation and phase II detoxification (e.g., glutathione and cysteine production). This can help practitioners:

• Detect if patients are favoring certain detox pathways.
• Determine if methylation support (through specific B vitamins) or cysteine support (through diet or supplements like NAC) is necessary.
• Monitor ammonia metabolism (high orotic acid can indicates excess ammonia) and glycine status. Pyroglutamic acid, (5-oxoproline), is a metabolite of glutathione and when high in the OAT could signal glycine deficiency (e.g., from glyphosate exposure and certain dietary practices) or glutathione depletion (indicating the body’s heightened demand for glutathione).

Interventions are individualized based on these markers, ensuring more precise biochemical support.

What Is the Advantage of Taking an Organic Acids Test Versus Other Tests?

Traditional diagnostic methods such as blood work or stool analysis often identify overt abnormalities but may miss subtle disruptions in metabolic pathways. The OAT fills this gap by providing a detailed “look under the hood” at the body’s biochemical pathways. Key advantages of the OAT include:

• Non-invasive and patient-friendly: This feature is especially valuable for pediatric patients or those averse to blood draws. The OAT requires only a urine sample, which can be collected at home.
• Broad-spectrum information: In a single test, practitioners can gain insight into dozens of metabolic pathways, from energy production and neurotransmitter synthesis to toxin exposure and micronutrient status.
• Functional markers: While stool tests may or may not detect the presence of bacteria or fungi by DNA or culture, OAT can uncover their metabolic activity, which mayto be missed inhelp confirm or challenge the validity of traditional tests. For example, measuring microbial byproducts not produced by humans allows the OAT to reveal bacterial or fungal overgrowth that may not be apparent in stool analyses.
• Pattern recognition: Because the OAT has been available for decades, test providers have collected data and developed expertise to recognize patterns and marker associations, making the test highly actionable and complementary to other tests. This includes.standard blood work and many functional labs, such as tissue analysis of essential elements and toxins, genomics testing, blood tests for folate receptor or other antibodies, specific mitochondrial tests, nutrient status, etc.
• Help clarify or support the findings of functional and structural assessments: This includes but is not limited to the areas of chiropractic health, intestinal health, neurobiology, psychology, mental health, reflex integration, optometry and more.
• Early detection: The OAT can reveal dysfunctions before symptoms manifest, allowing for proactive support and prevention of downstream health issues.

How Often Should an Organic Acids Test Be Run?

The OAT can be used:

• For initial assessment: When symptoms or health concerns warrant a deeper metabolic investigation.
• For routine “check-ins”: Even asymptomatic patients may benefit, as underlying dysfunctions can be caught early.
• Post-intervention follow-up: Retesting eight to 12 weeks after implementing therapeutic strategies can be helpful in determining efficacy so that clinical protocols can be adjusted if necessary.

Patients with chronic or changing health concerns may benefit from periodic reassessment if symptoms persist or new issues arise.

In Conclusion

The Organic Acids Test is a very useful tool used widely by functional medicine and other root-cause oriented health practitioners. By mapping metabolic pathways through urine analysis, practitioners can gain actionable insights that enable more targeted, effective interventions and perhaps even prevention of a wide variety of health conditions—from autism spectrum symptoms and mood disorders, to toxin exposure and digestive complaints.

About Maria Rickert Hong CHHC

Prior to working on Wall Street, she was a marketing specialist for Halliburton in New Orleans, where she also received her MBA in Finance & Strategy from Tulane University.

She is the author of the bestselling book Almost Autism: Recovering Children from Sensory Processing Disorder and the co-author of Brain Under Attack: A Resource for Parents and Caregivers of Children with PANS, PANDAS, and Autoimmune Encephalitis. She is a co-author of Reversal of Autism Symptoms among Dizygotic Twins through a Personalized Lifestyle and Environmental Modification Approach: A Case Report and Review of the Literature, J. Pers. Med. 2024, 14(6), 641.

Maria is also a Certified Holistic Health Counselor. Her work can be found on DocumentingHope.com, Healing.DocumentingHope.com, Conference.DocumentingHope.com and MariaRickertHong.com

About Heather Tallman Ruhm MD

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