A fascinating new study from scientists at the University of Leipzig has discovered that a specific immune function receptor, uniquely evolved in humans and great apes, is triggered by a metabolite from lactic acid bacteria (LAB) found in fermented foods.

Most mammals have two kinds of hydroxycarboxylic acid (HCA) receptors. These receptors are known to regulate immune function and energy homeostasis, primarily in response to dietary conditions. Around 15 years ago a third HCA receptor was discovered in the human genome, which further research revealed to be unique to humans and great apes.

A new study has now discovered that one of the strongest activators of this third HCA receptor is D-phenyllactic acid, a metabolite produced by lactic acid bacteria which appears in some foods as the fermentation process takes hold.