Origins and metabolism of trimethylamine in humans Download Scientific Diagram Trimethylaminuria, or fish odour syndrome is an uncommon condition that causes an unpleasant, fishy smell. The body is unable to turn a strong smelling chemical called trimethylamine produced in the gut when 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 TMAO (Trimethylamine oxide) biocrates life science