Dietary supplementation of l carnitine ameliorates metabolic syndrome independent of trimethylamine N oxide produced by gut microbes in high fat diet induced obese mice Food & Function (RSC Publishing) 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. Comparison of short term and long term effects of peroral L carnitine intake: clinical implications of elevated TMAO levels in cardiovascular complications Stabilizing the enzyme in fish odor syndrome Trimethylaminuria: Understanding and Treating Fish Odor Syndrome