Abnormally high levels of these microorganisms can cause or worsen behaviour disorders, hyperactivity, movement disorders, fatigue and immune function.

Many people with chronic illnesses and neurological disorders often excrete several abnormal organic acids in their urine. The cause of these high levels could include oral antibiotic use, high sugar diets, immune deficiencies, acquired infections, as well as genetic factors.
Mosaic Diagnostics Organic Acids Test also includes markers for vitamin and mineral levels, oxidative stress, neurotransmitter levels, and is the only OAT to include markers for oxalates, which are highly correlated with many chronic illnesses.

If abnormalities are detected using the OAT, treatments can include supplements, such as vitamins and antioxidants, or dietary modification. Upon treatment, patients and practitioners have reported significant improvement such as decreased fatigue, regular bowel function, increased energy and alertness, increased concentration, improved verbal skills, less hyperactivity, and decreased abdominal pain. The OAT is strongly recommended as the initial screening test.