TMAO and Heart DIsease
A focused but important (and astounding) research finding that has been developed by the Hazen lab and associates in recent years involves the gut microbiota and cardiovascular disease (CVD). Here's how it works: red meat contains a lot of phosphatidylcholine, which is part of animal cell membranes, and L-carnitine, which is involved with mitochondrial energy production. Gut microbes convert both of these compounds into something called trimethylamine, which travels through the bloodstream to the liver which converts it to trimethylamine N-oxide, or TMAO. TMAO causes arthrosclerosis and increases the risk of CVD, although the exact mechanisms aren't exactly clear. People who regularly eat red meat have more of the bacteria in their gut that are responsible for making TMAO than people who don't. While the link between high red meat consumption and CVD risk has been known for a long time, the involvement of the gut microbiota was a surprise when first reported.
Selected Scientific Literature
Wang et al., 2011: Gut flora metabolism of phosphatidylcholine promotes cardiovascular disease. (full text)
Koeth et al., 2013: Intestinal microbiota metabolism of L-carnitine, an nutrient in red meat, promotes artherosclerosis. (full text)
Tang et al., 2013: Intestinal microbial metabolism of phosphatidylcholine and cardiovascular risk. (full text)
Wang et al., 2014: Prognostic value of choline and betaine (for major adverse cardiac events) depends on intestinal microbiota-generated metabolite trimethyamine-N-oxide.
Koeth et al., 2013: Intestinal microbiota metabolism of L-carnitine, an nutrient in red meat, promotes artherosclerosis. (full text)
Tang et al., 2013: Intestinal microbial metabolism of phosphatidylcholine and cardiovascular risk. (full text)
Wang et al., 2014: Prognostic value of choline and betaine (for major adverse cardiac events) depends on intestinal microbiota-generated metabolite trimethyamine-N-oxide.