Revisiting the Role of Carnitine in Heart Disease Through the Lens of the Gut Microbiota Intestinal microbiota metabolism of l carnitine, a nutrient in red meat, promotes atherosclerosis Nature Medicine Cleveland Clinic researchers have discovered a connection between elevated blood levels of TMAO (trimethylamine N oxide)a byproduct of gut bacteria digestion of nutrients found in red meat and other animal productsand a higher Frontiers Acetyl L carnitine ameliorates atherosclerosis in LDLR mice by modulating cholesterol metabolism through SREBP2 dependent cholesterol biosynthesis