A recurring fishy odor could indicate a larger medical problem. Malodorous biogenic amines in Escherichia coli caused urinary tract infections in womena metabolomics approach Scientific Reports Correlation between the trimethylamine (TMA) concentration and the Download Scientific Diagram Did You Know? Some people report a fishy smell after supplementing with L carnitine. This happens because certain gut bacteria convert carnitine to trimethylamine, a malodorous compound found in rotting fish. Ever heard of Fish Odor Syndrome? Its a rare condition where the body cant break down trimethylamine a compound found in foods like fish, eggs, and beans. This leads to a strong, fish like smell