Study reveals new details on how byproduct formed by eating red meat can harm the heart

Photo shows large piece of raw beef steak.

Researchers are reporting new details on how a diet rich in red meat can harm the heart.  The findings could lead to new interventions to prevent or reduce this risk, researchers say. 

Past studies by the research group showed that a chemical byproduct forms when gut bacteria digest certain nutrients found in red meat. The byproduct, called TMAO (trimethylamine N-oxide), increases the risk of heart disease and stroke by promoting blood clotting and atherosclerosis. The new findings provide additional details about the biochemical and genetic process by which gut microbes convert the nutrient carnitine, which is abundant in red meat, into TMAO following the ingestion of red meat.  

In a study involving humans and mice, the researchers identified a gut microbial gene cluster involved in the transformation of carnitine into a precursor molecule, gamma-butyrobetain, or gamma-BB. That molecule is eventually converted into trimethylamine (TMA), the precursor of TMAO. The researchers named the newly discovered gene cluster the gnu (gamma-butyrobetaine utilization) gene cluster. 

The discovery of the gene cluster could lead to new therapeutic targets to prevent or reduce diet-associated cardiovascular risk associated with red meat, the researchers said. The study, partly funded by NHLBI, appeared in Nature Microbiology.