Researchers have discovered that humans and great apes possess a receptor on their cells that detects metabolites from bacteria commonly found in fermented foods and triggers movement of immune cells. Claudia Stäubert of the University of Leipzig report these findings in a study published 23rd May in PLOS Genetics.
Consuming lactic acid bacteria can offer many health benefits, but scientists still don't understand, on a molecular level, why it is helpful to ingest these bacteria and how that affects our immune system. Initially the researchers were investigating proteins on the surface of cells called hydroxycarboxylic acid (HCA) receptors.
Most animals have only two types of this receptor but humans and great apes have three. The researchers discovered that a metabolite produced by lactic acid bacteria, D-phenyllactic acid, binds strongly to the third HCA receptor, signaling the immune system their presence. The researchers propose that the third HCA receptor arose in a common ancestor of humans and great apes, and enabled them to consume foods that are starting to decay.
The study yields new insights into the evolutionary dynamics between microbes and their human hosts and opens new research directions for understanding the multiple positive effects of eating fermented foods.
