Cheap protein = expensive gut problems. Here's what to look for on the label before you buy What Is Carnitine? TMAO? What's Their Link To Red Meat? Pritikin Intestinal microbiota metabolism of l carnitine, a nutrient in red meat, promotes atherosclerosis Nature Medicine JCI l Carnitine in omnivorous diets induces an atherogenic gut microbial pathway in humans Differential effects of oral and intravenous L carnitine on serum lipids: is the microbiota the answer?