Full article: Gut microbes with the gbu genes determine TMAO production from L carnitine intake and serve as a biomarker for precision nutrition Simultaneous quantification of trimethylamine oxide and its precursors from gut microbial metabolic pathway Carnitine metabolism in the human gut: characterization of the two component carnitine monooxygenase CntAB from Acinetobacter baumannii Journal of Biological Chemistry JCI The contributory role of gut microbiota in cardiovascular disease Cheap protein = expensive gut problems. Here's what to look for on the label before you buy