Most people living with unexplained symptoms share a familiar frustration: the tests come back fine, the doctor says everything looks normal, and yet something is clearly wrong. You are tired in a way that sleep does not fix. Your mood feels unpredictable. Your digestion is off. Your brain is foggy. And nobody can give you a reason.

The problem, more often than not, is not that nothing is wrong. It is that the wrong tests are being run.

Standard lab panels are designed to detect disease that has already fully developed. They flag the end result, not the process leading up to it. What they do not measure is the underlying metabolic dysfunction, the gut bacteria producing neurological toxins, the fungal overgrowth generating systemic inflammation, or the nutritional depletions quietly undermining every system in your body.

That is exactly what the Organic Acids Profile (OAp) from Diagnostic Solutions Laboratory is designed to reveal. You can order the OAp directly through Canada GI Map here, no doctor referral required.

The OAp is a urine-based metabolic profiling test that uses advanced LC-MS/MS technology to evaluate dozens of metabolites across multiple biological categories. It gives practitioners and health-conscious individuals a systems-level view of what is happening in the body, using a metabolomics approach that goes well beyond traditional nutritional testing. It identifies patterns of accumulation and depletion across energy metabolism, gut microbial activity, neurotransmitter function, and vitamin and mineral status, and it does all of this from a single first-morning urine sample collected in the comfort of your own home.

You can view the Diagnostic Solutions OAp sample report here to see how the markers are organized and what the reporting format looks like before you order.

Below are five markers from the OAp that I consider the most clinically significant, the most frequently misunderstood, and the most likely to explain the kinds of chronic symptoms that standard testing routinely misses.

Why Organic Acids Testing Works Where Standard Blood Panels Fall Short

Before getting into the individual markers, it is worth understanding why this type of test captures information that conventional bloodwork simply cannot.

Every metabolic process in your body produces intermediate compounds called organic acids. These compounds are filtered through the kidneys and excreted in urine, which makes a urine sample a surprisingly rich source of metabolic information. When something is disrupted upstream, the organic acids downstream tell the story.

If a specific enzyme is blocked, its substrate accumulates and shows up elevated in urine. If a particular bacterium is overgrowing in your gut, its metabolic waste products appear in urine. If your mitochondria are not running efficiently because of a vitamin deficiency, the backup metabolites can be measured in urine. The OAp reads these patterns and translates them into a metabolic signature that is unique to each individual.

Diagnostic Solutions describes this as a systems-biology approach to testing, and that framing is accurate. You are not just looking at single numbers in isolation. You are looking at patterns across interconnected pathways that reveal how your body is actually functioning, not just whether you fall inside or outside a population reference range.

For Canadians who want access to this level of metabolic insight without requiring a specialist referral, the OAp is available to order directly through Canada GI Map here.

OAp Marker #1: Quinolinic Acid and the Neuroinflammation Signal

The Stress and Mood section of the Diagnostic Solutions OAp includes a marker that most people have never encountered before, and it is one of the most important on the entire panel: quinolinic acid.

The Diagnostic Solutions sample report describes quinolinic acid directly as a neuroinflammatory marker, and that description does not overstate its significance.

Quinolinic acid is a downstream metabolite of tryptophan, produced along a pathway called the kynurenine pathway. Under normal conditions, this pathway converts tryptophan through a series of steps that eventually produce NAD+, a molecule every cell requires for energy production. Quinolinic acid is an intermediate in this process, and when the enzyme responsible for converting it forward is functioning well, it does not accumulate.

But that enzyme, QPRT, is sensitive to inhibition. Inflammation inhibits it. Certain environmental toxins, particularly phthalates found in plastics and synthetic personal care products, inhibit it. When QPRT is slowed, quinolinic acid builds up in circulation and in brain tissue. And elevated quinolinic acid is not metabolically neutral.

It is a potent NMDA receptor agonist, meaning it overstimulates glutamate receptors in the brain and triggers a calcium flood into neurons that leads to oxidative stress, mitochondrial damage, and, in sustained cases, neuronal death. It has also been associated with disruption of the blood-brain barrier. The immune cells that are supposed to protect the brain, including macrophages and microglia, are the primary producers of quinolinic acid during states of immune activation and inflammation. In other words, the more inflamed you are, the more your own immune system produces this compound.

Elevated quinolinic acid has been associated in research with depression, anxiety, cognitive decline, and neurological conditions more broadly. The Diagnostic Solutions OAp report lists antioxidants including vitamin D, polyphenols, EPA/DHA, and magnesium as intervention considerations, alongside avoiding phthalates and evaluating B6 status.

Importantly, the OAp also measures picolinic acid alongside quinolinic acid. Picolinic acid is a neuroprotective compound that counterbalances quinolinic acid activity. The ratio between the two provides additional clinical insight that individual marker values alone cannot convey. Elevated quinolinic acid in the context of low picolinic acid tells a more alarming story than elevated quinolinic acid when picolinic acid is also appropriately elevated.

This kind of pattern-level interpretation is where functional testing earns its value.

OAp Marker #2: 4-Cresol and the Gut Bacteria That Disrupt Your Dopamine

When the gut microbiome is healthy and balanced, it supports brain chemistry. When it is disrupted by pathogenic overgrowth, it can produce compounds that actively interfere with neurotransmitter function. 4-cresol is one of the most clearly documented examples of that interference.

4-cresol is a metabolite produced by pathogenic Clostridium bacteria in the gut, most notably Clostridioides difficile and related species. These are not the beneficial, butyrate-producing clostridia that a healthy gut microbiome requires. These are opportunistic pathogens that proliferate when beneficial bacteria are depleted, often following antibiotic exposure, a high-sugar diet, chronic stress, or immune dysregulation.

The mechanism of harm is specific and well-characterized. 4-cresol inhibits an enzyme called dopamine beta-hydroxylase, which is responsible for the conversion of dopamine into norepinephrine. When this conversion is blocked, dopamine accumulates in nerve endings and neurons. Excess dopamine does not simply produce a pleasant mood surplus. It gets oxidized into toxic dopamine quinones that damage neural tissue. Simultaneously, the resulting deficiency of norepinephrine disrupts the sympathetic nervous system, contributing to poor concentration, emotional dysregulation, fatigue, and impaired stress response.

What makes 4-cresol such an actionable marker on the OAp is that it points directly to a specific cause and a specific mechanism. When it is elevated, you know Clostridium overgrowth is present, you know how it is affecting brain chemistry, and you have a clear starting point for an antimicrobial protocol targeting those specific organisms.

Pairing the 4-cresol finding with neurotransmitter metabolite markers on the same report, particularly homovanillic acid (HVA), which reflects dopamine turnover, creates a pattern that tells a coherent story about gut-to-brain disruption that no conventional panel would identify.

OAp Marker #3: HPHPA and the Brain Chemistry Connection Most Doctors Have Not Made

While 4-cresol appears as the primary Clostridium marker in approximately 15 percent of positive OAp findings, a related compound called HPHPA (3-(3-hydroxyphenyl)-3-hydroxypropionic acid) is the more frequently elevated marker, appearing in roughly 80 percent of Clostridium-positive OAp results.

HPHPA is also produced by pathogenic Clostridium species, and it also inhibits dopamine beta-hydroxylase through the same mechanism as 4-cresol. The result is the same type of dopamine accumulation, toxic quinone formation, and norepinephrine deficiency, which means the neurological effects are closely parallel.

What distinguishes HPHPA in the clinical research literature is how consistently and dramatically it shows up in specific populations. Dr. William Shaw’s foundational research identified HPHPA in urine samples from patients with autism and schizophrenia at concentrations far exceeding those of control groups. In some severe cases, HPHPA was the single most concentrated organic acid in the entire urine sample, appearing at levels many times higher than the next most elevated compound.

This research shifted how a generation of functional practitioners understand the relationship between gut microbial activity and neurological and behavioral symptoms. The gut is not simply digesting food. When the wrong bacteria take hold, it becomes a factory producing neurological toxins that enter systemic circulation, influence neurotransmitter metabolism, and affect brain function in ways that have historically been attributed entirely to the brain itself.

For adults dealing with mood instability, unexplained anxiety, poor focus, or behavioral challenges that have not responded to conventional approaches, elevated HPHPA is a finding that deserves serious clinical attention. It is also one that most standard labs are not looking for.

OAp Marker #4: Oxalates and the Systemic Disruptor Hiding in Your Healthy Diet

This is the marker that tends to produce the most surprise, particularly among people who consider themselves health-conscious eaters. If you have built a daily routine around green smoothies, nut-based snacks, dark chocolate, and leafy salads, you may be consuming more oxalates than your system can comfortably process.

Oxalic acid and its salt form, oxalates, enter the body from three primary sources: diet, gut microbial activity (particularly from fungal and yeast species), and human metabolism. The OAp measures urinary oxalate levels and, when elevated, helps distinguish which of these sources is the primary driver.

Among the most common dietary oxalate contributors are spinach, almonds, beets, Swiss chard, sweet potatoes, and dark chocolate, all of which appear frequently in therapeutic, paleo, and ketogenic diets. People adopting these eating approaches in good faith often have no idea they are simultaneously loading their system with oxalates.

The gut-derived route is equally significant. Aspergillus and Candida species use glyoxalate as an intermediate in their energy-producing pathways and release oxalates as a byproduct. When fungal overgrowth is present in the gut and confirmed by elevated fungal markers on the OAp, elevated oxalates frequently appear alongside those markers. Treating the fungal overgrowth typically reduces oxalate production, but the oxalate burden can temporarily spike during die-off before it normalizes.

The systemic effects of chronically elevated oxalates are broader than most people realize. Oxalates bind calcium and can crystallize and deposit in soft tissues, including the kidneys, joints, muscles, and connective tissue. People with unexplained muscle pain, chronic joint stiffness, fibromyalgia-like presentations, or vulvodynia frequently have elevated oxalates on their OAp. High oxalate burden also impairs mitochondrial enzyme function, creating a fatigue profile that compounds any existing energy-production deficits. And because oxalates chelate calcium and magnesium out of circulation, they create downstream mineral imbalances that affect nerve conduction, muscle function, and mood stability.

The OAp is currently one of the most practical clinical tools available for assessing oxalate status. Its value is not just in detecting elevation but in helping identify the source, which is the starting point for an effective treatment strategy.

OAp Marker #5 (The One Most People Miss): Lactic Acid as a Functional B1 Deficiency Signal

This is the marker I want to make sure you do not overlook, because it is one of the most clinically impactful patterns on the OAp and one of the least discussed in general health conversations.

The Diagnostic Solutions sample report specifically notes that elevated lactic acid levels are seen in anaerobic or metabolic conditions associated with inflammation, and that supplementation with B1, CoQ10, and lipoic acid is a relevant intervention consideration. That note about B1 is significant, and here is why.

Lactic acid accumulates when pyruvate, the end product of glucose breakdown, cannot efficiently enter the mitochondria for energy production. The gateway for that entry is an enzyme complex called pyruvate dehydrogenase (PDH), and PDH requires thiamine, vitamin B1, as an essential cofactor. Without adequate thiamine, PDH slows down, pyruvate backs up, and the body converts that excess pyruvate to lactic acid as a metabolic workaround.

When the OAp shows elevated lactic acid alongside elevated pyruvic acid, the combined pattern is a functional indicator of thiamine insufficiency, and this is important: this pattern can appear before a standard serum thiamine test ever comes back abnormal. Blood levels of thiamine can look normal while cells are functionally depleted, particularly under conditions of high metabolic demand.

The people most at risk for functional B1 deficiency are those eating a high-carbohydrate diet (carbohydrate metabolism burns through thiamine at an accelerated rate), people who consume alcohol regularly, people who drink large daily quantities of coffee or tea (the tannins in both impair thiamine absorption), and anyone under chronic physical or oxidative stress.

The symptoms of subclinical thiamine deficiency are frustratingly nonspecific: persistent fatigue that rest does not resolve, heart palpitations, tingling or numbness in the extremities, anxiety, difficulty concentrating, poor memory, and disproportionate exhaustion after carbohydrate-heavy meals. Because these symptoms overlap with so many other conditions, B1 insufficiency rarely gets considered in conventional clinical contexts.

The OAp gives you a functional window into this deficiency through the lactic acid and pyruvic acid pattern, and the response to thiamine supplementation when this pattern is present is frequently dramatic and rapid. It is one of those findings that makes you wonder how long it might have been overlooked if you had never run the test.

How These Five Markers Interact With Each Other

One of the things that sets the OAp apart as a clinical tool is the way its markers speak to each other. These five findings often appear together, not by coincidence but because of the interconnected nature of the systems they reflect.

Elevated quinolinic acid frequently coexists with systemic inflammation and oxidative stress, the same conditions that deplete thiamine and impair mitochondrial function, which in turn raises lactic acid. A dysbiotic gut environment permissive enough to support Clostridium overgrowth and elevated HPHPA and 4-cresol is also typically an environment where fungal species thrive and oxalate production rises. Mitochondrial dysfunction from elevated oxalates and B1 deficiency creates further oxidative stress, which feeds back into the kynurenine pathway and pushes more tryptophan toward quinolinic acid production.

These are not five separate problems. They are five expressions of one interconnected metabolic picture. The OAp does not just measure them in isolation. It gives you the data to see how they relate, prioritize where to intervene, and track whether those interventions are shifting the underlying biochemistry.

That feedback loop, test, treat, and retest, is how functional medicine creates lasting clinical change rather than symptom management. And it starts with getting the right data.

Who Should Consider the OAp?

This test tends to be most valuable for people experiencing any of the following:

Neurological and mood-related concerns: anxiety, depression, brain fog, memory difficulties, mood instability, or cognitive fatigue that has not responded to conventional care.

Energy and mitochondrial issues: chronic fatigue, post-exertional malaise, or exhaustion that no amount of rest resolves.

Gut-related symptoms: bloating, irregular bowel habits, food sensitivities, a history of repeated antibiotic use, or a sense that gut health is influencing mood or cognition.

Chronic pain and inflammation: unexplained muscle aches, joint pain, fibromyalgia-like presentations, or widespread inflammatory conditions without an identified cause.

Complex chronic illness: autoimmune conditions, mold exposure history, or any situation where gut dysbiosis, toxic burden, and nutrient depletion are likely contributing to a multisystem picture.

Children and adults on the autism spectrum: where Clostridia overgrowth, dopamine disruption, and oxalate burden are documented metabolic contributors frequently left unaddressed in standard care.

If you have been told your labs are normal but you know something is not right, the OAp is often the test that begins to provide real answers. It adds a layer of metabolic specificity and actionability that conventional testing cannot match.

Order the Organic Acid Test OAp directly through Canada GI Map, no referral required.

How to Order and What to Expect

Ordering through Canada GI Map is straightforward. The OAp from Diagnostic Solutions Laboratory is available at USD $425 and ships directly to you as a home collection kit within five to seven business days of ordering. You collect a first-morning urine sample, ship it back to the lab using the included materials, and receive your results securely by email within approximately twelve to sixteen business days.

The report is organized by functional category, including energy and mitochondrial processing, stress and mood markers, gut microbial activity, toxic impact markers, and nutritional status. The summary page highlights the most significant findings so you can see the big picture immediately, with detailed explanations on the following pages for each individual marker.

Working with a practitioner who has experience reading OAp results will help you extract maximum clinical value from the report, particularly when multiple markers interact in patterns like the ones described here. That said, even a solo review of your results alongside quality educational resources gives you a foundation for informed conversations with your healthcare provider.

View the Diagnostic Solutions OAp sample report so you know exactly what to expect before your results arrive.

Your symptoms are not random. Your body is producing data. The OAp is the tool that reads it.

About Canada GI Map

Canada GI Map was created to give Canadians direct, affordable access to the functional lab tests that can genuinely change their health trajectory. The philosophy is straightforward: you should not have to navigate a fragmented healthcare system, wait months for a specialist, or accept incomplete answers when the tools to understand your own biology already exist. Whether you are exploring gut health, brain function, immune resilience, metabolic health, or the gut-brain connection that ties all of those together, Canada GI Map gives you access to the same advanced testing used by leading functional medicine practitioners, ordered on your timeline, with results delivered securely and privately to you. Confidential. Affordable. Convenient. That is what this site is here to provide.

These statements are for educational purposes and are not intended to diagnose, treat, cure, or prevent any disease. Always work with a qualified healthcare practitioner to interpret lab results and guide treatment decisions.

References

1. Guillemin GJ. “Quinolinic acid, the inescapable neurotoxin.” The FEBS Journal. 2012;279(8):1356-1365. doi:10.1111/j.1742-4658.2012.08485.x — Landmark review establishing quinolinic acid as a brain endogenous excitotoxin produced by macrophages and activated microglia during neuroinflammation, acting via NMDA receptor agonism and disruption of the blood-brain barrier.
2. Mosaic Diagnostics. “How the Organic Acids Test Provides Insights into Toxic Exposures.” MosaicDX.com, 2024. https://mosaicdx.com/resource/how-the-organic-acids-test-provides-insights-into-toxic-exposures/ — Describes the mechanism by which environmental phthalates inhibit the enzyme converting quinolinic acid to nicotinamide, causing QA accumulation and downstream neuroinflammation.
3. Shaw W. “Increased urinary excretion of a 3-(3-hydroxyphenyl)-3-hydroxypropionic acid (HPHPA), an abnormal phenylalanine metabolite of Clostridia spp. in the gastrointestinal tract, in urine samples from patients with autism and schizophrenia.” Nutritional Neuroscience. 2010;13(3):135-143. doi:10.1179/147683010X12611460763968 — Foundational paper identifying HPHPA and 4-cresol as Clostridium metabolites significantly elevated in urine samples from patients with autism and schizophrenia.
4. Shaw W. “Inhibition of Beta-oxidation Pathway of Fatty Acids and Dopamine-Beta-Hydroxylase by Phenyl Derivatives of Short-Chain Fatty Acids from Gastrointestinal Clostridia Bacteria is a Major Cause of Autism.” Published via Mosaic Diagnostics / PubMed. PMID: 37363147. — Details the mechanism by which HPHPA and 4-cresol inhibit dopamine beta-hydroxylase, leading to dopamine accumulation, norepinephrine deficiency, and toxic dopamine quinone production in the brain.
5. Passmore IJ, Letertre MPM, Preston MD, et al. “Clostridioides difficile infection increases circulating p-cresol levels and dysregulates brain dopamine metabolism: linking gut-brain axis to autism and other neurologic disorders.” bioRxiv (preprint). 2021. doi:10.1101/2021.10.22.465382 — Demonstrates that C. difficile infection drives elevated circulating p-cresol (4-cresol), inhibits dopamine beta-hydroxylase, and disrupts dopaminergic signaling in brain regions relevant to neurodevelopmental disorders.
6. Pascucci T, Colamartino M, Fiori E, Sacco R, Coviello A, Ventura R, et al. “P-cresol Alters Brain Dopamine Metabolism and Exacerbates Autism-Like Behaviors in the BTBR Mouse.” Brain Sciences. 2020;10(4):233. doi:10.3390/brainsci10040233 — Animal model study confirming that 4-cresol exposure directly alters brain dopamine metabolism and amplifies autism-like behavioral phenotypes.
7. Mosaic Diagnostics. “Guide to Oxalate Test Results.” MosaicDX.com, 2024. https://mosaicdx.com/resource/oxalates-great-plains-laboratory/ — Clinical overview explaining how Candida and Aspergillus species produce oxalates via glyoxalate pathway intermediates, and how proportional vs. disproportional oxalate elevations guide clinical interpretation.
8. Mosaic Diagnostics. “Oxalate Control.” MosaicDX Clinical Reference Document. https://mosaicdx.com/wp-content/uploads/2023/02/GPL_Oxalate-Control.pdf — Reviews the three primary sources of urinary oxalates (diet, fungal overgrowth, and human metabolism) and management strategies including calcium-magnesium citrate supplementation.
9. HealthMatters.io. “Oxalic Acid — Organic Acids Test (OAT) Biomarker Explanation.” https://healthmatters.io/understand-blood-test-results/oxalic — Summarizes the clinical significance of elevated urinary oxalates on the OAT, including associations with kidney stones, fibromyalgia, vulvodynia, autism, muscle pain, and cardiac abnormalities.
10. MedLink Neurology. “Thiamine (B1) Deficiency.” Updated 2025. https://www.medlink.com/articles/thiamine-deficiency — Comprehensive neurological reference establishing that impaired pyruvate dehydrogenase activity from thiamine deficiency leads to elevated pyruvate and lactate, noting that subclinical thiamine deficiency presents with vague symptoms including fatigue, irritability, headache, and lethargy long before overt neurological signs appear.
11. Donnino M. “Effect of Thiamine on Pyruvate Dehydrogenase Activity in Septic Shock.” NIH Grant K02-HL107447-01A1. — NIH-funded research establishing thiamine as an essential cofactor for the pyruvate dehydrogenase complex, confirming that thiamine deficiency causes anaerobic metabolism predominance and lactic acidosis, and that thiamine administration can rapidly reverse this biochemical pattern.
12. Diagnostic Solutions Laboratory. “Organic Acids Profile (OAp) Urine — Sample Report and Clinical Reference.” DiagnosticSolutionsLab.com, 2024. https://www.diagnosticsolutionslab.com/assets/documents/organic-acids-profile-urine-sample-report.pdf — The official Diagnostic Solutions OAp sample report, confirming LC-MS/MS methodology, marker categories including energy and mitochondrial processing, stress and mood (quinolinic acid, picolinic acid, VMA), gut microbial activity, toxic impact markers, and nutritional status, with intervention considerations for each finding.