Trimethylaminuria: Understanding and Treating Fish Odor Syndrome Alimentos ricos en carnitina: Entendiendo la L carnitina y sus beneficios Loyal L carnitina, propiedades y beneficios para nuestro cuerpo 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. JCI l Carnitine in omnivorous diets induces an atherogenic gut microbial pathway in humans