Some of the adverse effects associated with eating red meat are mediated by gut bacteria. Red meat contains large amounts of L-carnitine, a nutrient that gut microbes convert into trimethylamine (TMA). In the liver, TMA becomes trimethylamine N-oxide (TMAO), which is known to hasten the formation of arterial plaques that can lead to heart attacks and strokes.
A new study of mice genetically prone to atherosclerosis, published yesterday (November 4) in Cell Metabolism, has found that other types of gut microbes produce a different molecule, gamma-butyrobetaine, at a 1,000-fold higher rate than TMA, a process that also leads to TMAO formation and atherosclerosis.
Previously, gamma-butyrobetaine was thought to be a precursor, but not a product, of L-carnitine. Researchers from the Cleveland Clinic and their colleagues ...