A new German study found that a receptor found in humans and humanoid cells can detect metabolites of common bacterial lactic acid bacteria in fermented foods, and when combined, can signal “activate” the immune system.
The results of this study will help find potential drug targets for the treatment of inflammatory diseases.
A cell receptor is a protein that allows a specific signal to enter a cell when it is bound to the cell. Most animals have only two HCA receptors, but a third HCA receptor is also present in humans and apes. The researchers found that a metabolite produced by lactic acid bacteria, D-phenyl lactic acid, binds to a third HCA receptor and signals immune cells to trigger immune cell activity.
The study suggests that the third type of HCA receptor first appeared in the common ancestor of humans and apes, and this evolutionary character changed the eating habits of human ancestors, allowing them to start eating fermented foods, such as fruits that have begun to rot.
One of the authors, Stuart, a researcher at the University of Leipzig in Germany, said that in the future they will further study how the lactic acid bacteria metabolite D-phenyl lactic acid affects the immune system.