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. Frontiers The potential links between human gut microbiota and cardiovascular health and disease is there a gut cardiovascular axis? Pure Balance Dry Dog Food for Sensitive Skin and Stomach with Salmon & Rice, 16 lbs Walmart.com L carnitine tartrate supplementation in the fight against infectious disease L Carnitine: Benefits, Uses, and Side Effects Lifespan Research Institute 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.