Comparison of short term and long term effects of peroral L carnitine intake: clinical implications of elevated TMAO levels in cardiovascular complications L Carnitine & Arterial Plaque Butyrobetaine Is a Proatherogenic Intermediate in Gut Microbial Metabolism of L Carnitine to TMAO ScienceDirect Atherosclerosis Linus Pauling Institute Oregon State University MedicalResearch.com Study Examines Link Between L Carnitine and Atherosclerosis 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