Trimethylaminuria: FMO3 mutations that cause malodorous body odor Stabilizing the enzyme in fish odor syndrome Trimethylamine and Trimethylamine N Oxide, a Flavin Containing Monooxygenase 3 (FMO3) Mediated Host Microbiome Metabolic Axis Implicated in Health and Disease Drug Metabolism and Disposition Potential Adverse Effects of L Carnitine Marnys 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. jcdr 18 WE01 g001.jpg