OAT Testing an Overview

Dr. Eve Henry, MD
OAT Testing an Overview

Organic Acid Testing (OAT) can aid advanced practitioners in detecting imbalances, toxicity, and inflammation in patients and indicate the functional need for specific nutrients, diet modification, antioxidant protection, and detoxification.

On a cellular level, our bodies are a constant stream of chemical reactions. These chemical reactions are the building blocks of our whole physiologic system, and our health is dependent on their optimal function.

The OAT test captures byproducts of these chemical reactions called Organic Acids that we excrete in our urine. By capturing the relative amounts of these organic acids, we are able to gather information on how these chemical reactions in our bodies are functioning. If a chemical reaction is going too slowly, for example, there can be a buildup of specific organic acids in the urine.

The OAT Test is a urine test that makes it exceptionally easy for patients to do at home and is very helpful in populations such as pediatrics, where blood draws can be a challenge. The kidney does not significantly reabsorb organic Acids, so they are concentrated and readily detected in urine. Once the first-morning void is collected and shipped to the lab, gas or liquid chromatography linked with mass spectrometry are used to identify the organic acid compounds within the urine.


Why would I order an OAT test?

The most common mainstream clinical use for Organic Acid testing is newborn screening for organic acid disorders. These rare, inherited disorders cause enzyme deficiencies that can be extremely harmful to newborns. Enzymes are the main driver for chemical reactions, so when an enzyme is missing or deficient, the chemical reaction slows down or stops. This physiologic problem is captured by rising levels of specific organic acids in the newborn’s blood or urine. The OAT gives you insight into the enzymatic problem occurring on a cellular level.

Using that same principle, Functional medical practitioners use the OAT test to get a snapshot of many aspects of an individual’s metabolic and cellular health.  These tests can detect alterations in the gut microbiome, vitamin deficiencies, levels of neurotransmitters, and exposures to mold or fungus.

OAT testing is broad and can be an excellent first-line test if you don’t know exactly what type of problem you are looking for. With one easy intervention, you can gather a number of clues on multiple aspects of someone’s physiology.

Top 4 Most Popular OAT Test Ordered by Rupa Health Practitioners

  • OAT by Vibrant America
  • OAT by Great Plains
  • OAT by DUTCH
  • Nutra Eval FMV by Genova

Points to Consider When Ordering an OAT Test:

  1. The OAT results reflect byproducts of metabolism from the last 12-48 hours.
  2. It is important to realize with urine OAT testing that you are capturing information regarding a short window of time. Physiology moves fast and blood is filtered by the kidney at a rate of 120 mL per minute. The OAT captures the organic acids that resulted from physiologic processes about 12-48 hours prior to that test.
  3. Remind your patient to eat their usual diet and be cautious of certain foods. The vital impact of diet on one’s health is evident with OAT testing. I have gotten significantly different results on OAT testing when the individual was eating an unhealthy diet vs. when they specifically tried to improve their diet for the test. If you are trying to discern how someone’s diet affects their health, make sure they do their usual dietary routine in the two days leading up to their test.
  4. The OAT test results can also be altered by eating certain foods. Remind your patients to avoid apples, grapes (yes, this means wine), raisins, pears, and cranberries in the days leading up to the test.
  5. The OAT is rarely the final test.

While some practitioners may use OAT testing as a stand-alone evaluation, it is commonly used as an initial guide. If an OAT test points to a problem in the microbiome by revealing an excess of organic acids related to dysbiotic bacteria, you can then follow up with focused stool testing. It is a fantastic first step when working with a new patient or something to try when you aren’t sure what direction to move in next.

In a nutshell - the OAT offers a quick and easy peek into many aspects of our cellular health. It is an excellent first-line test and can provide helpful clues as you look for root cause problems in someone’s health. The OAT can be dramatically affected by diet and reflects only recent physiologic patterns, so it is vital to have a clear understanding of your patient’s diet in and around the time of this test.

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Dr. Eve Henry, MD
Rupa Advisor
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