Trimethylamine N oxide (TMAO) is a small molecule produced in humans primarily by the gut liver axis and has become an important biomarker, and possible mediator, of cardiometabolic and renal disease. Dietary choline, phosphatidylcholine ( The Intricate Gut Heart Connection; The Role of Gut Microbiota in the Pathogenesis of Cardiovascular Disease Advances in Clinical and Experimental Medicine Pathobiological Relationship of Excessive Dietary Intake of Choline L Carnitine: A TMAO Precursor Associated Aggravation in Heart Failure in Sarcopenic Patients Intestinal microbiota metabolism of l carnitine, a nutrient in red meat, promotes atherosclerosis Nature Medicine Frontiers Gut Metabolite Trimethylamine N Oxide in Atherosclerosis: From Mechanism to Therapy