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Halitosis or bad breath can create embarrassing social situations for some people. Bad breath usually originates in the oral cavity, but in rare instances, it can be a systemic problem. One such cause is a genetic disease named trimethylaminuria, which is a metabolic disorder of the gastrointestinal tract according to the International Journal of Oral Science. Here’s what you need to know about the disorder and how it affects your oral heath.


If you have this disorder, you have an inherited enzyme deficiency. Bacteria in the stomach produce trimethylamine from the precursors of trimethylamine-N-oxide and choline. It has a fishy odor, but it is normally converted back into trimethlamine in the liver by actions of an enzyme, and this by-product is typically odorless.

But if you lack the enzyme then there is an accumulation of trimethylamine, which is eventually excreted in the urine. Although much of the trimethylamine is found in the urine, it can also be found in sweat and the breath, causing an odor that has a distinct, fishy smell. The combination of this bad breath and body odor can diminish your self-confidence.

Trimethylaminuria Diagnosis and Treatment

In order to determine a diagnosis, your physician must rule out other disorders that may be causing uncontrollable body odor. In a suspected case of trimethylaminuria, a urine sample is analyzed to determine the trimethylamine and trimethylamine-N-oxide levels.

Trimethylaminuria symptoms are managed through diet adjustments, such as avoiding fish and other foods high in trimethylamine-N-oxide. Sometimes antibiotics are prescribed to attempt to correct your stomach’s flora (or bacteria). Activated charcoal can also be used to try to bind the trimethylamine in the stomach.

Effects on Your Oral Health

While there is no known or documented negative effect of trimethylaminuria on the teeth or gums, it is a potential cause of bad breath. The tongue is the area most likely to host the bacteria that cause bad breath, so a toothbrush with a built-in tongue scraper, like the Colgate® Total 360°® Flossing Toothbrush, can help scrub away this bacteria. In the end, however, don’t forget this is a medical problem that requires intervention from your dentist and physician.

To keep bad breath at bay, no matter of its origin, good oral hygiene goes a long way. Consider a daily regimen of mouthwash and toothpaste and invest in a quality toothbrush to freshen your breath and restore your confidence.