Comparison of short term and long term effects of peroral L carnitine intake: clinical implications of elevated TMAO levels in cardiovascular complications Intestinal microbiota metabolism of l carnitine, a nutrient in red meat, promotes atherosclerosis Nature Medicine Dietary allicin reduces transformation of L carnitine to TMAO through impact on gut microbiota ScienceDirect Dietary allicin reduces transformation of L carnitine to TMAO through impact on gut microbiota ScienceDirect