What makes good bacteria good? Positive influences of lactic acid bacteria on immune health examined in new research
Proteins on the surface of cells called hydroxycarboxylic acid (HCA) were found to detect lactic acid bacteria, stimulating immune cells
27 May 2019 --- University of Leipzig, Germany, research has revealed that consuming lactic acid bacteria – responsible for the fermentation in food and beverages – triggers movement in immune cells, which facilitates overall immune system wellness. The study, published in PLOS Genetics, also found that proteins on the surface of cells called hydroxycarboxylic acid (HCA) are responsible for the detection of this bacteria and may have played a key role in the evolutionary adaptation of our bodies to the consumption of acidified foods. The study yields new insights into the evolutionary dynamics between microbes and their human hosts and opens new research avenues for understanding the multiple positive effects of eating fermented foods.
Most animals have only two types of this HCA 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, such as fruits picked up from the ground.
The study yields new insights into the evolutionary dynamics between microbes and their human hosts. “We are convinced that this receptor very likely mediates some beneficial and anti-inflammatory effects of lactic acid bacteria in humans,” says lead author Claudia Stäubert. “That is why we believe it could serve as a potential drug target to treat inflammatory diseases.”
Future studies may reveal the details of how D-phenyllactic acid impacts the immune system, and whether the metabolite also affects fat cells, which also carry the third HCA receptor on their surfaces. The impact of gut microbes on overall health and wellness has been exemplified in multiple recent studies, which demonstrate their efficacy in reducing aging to promoting heart health.
Many players within the dairy and nutrition industries are expanding their businesses through cultivating in-depth knowledge of lactic acid bacteria. In March, Yakult launched a new synbiotic drink to the South Korean market, MPRO3, which combines three classes of active bacteria that interact with the gut microbiota and overall gut health, including three kinds of patented lactic acid bacteria.
