Probiotics Benefit More Than Just the Gut

December 22, 2011

Could probiotic rich foods help you de-stress? A new study out of Ireland says most likely. Find out more here

Good digestive health may help to regulate and reduce stress in the brain, according to a recent study out of University College Cork in Cork, Ireland. The study looked at how potential probiotics (not found in foods yet), affected the brain function of mice, and found that the presence of a specific probiotic in the gut altered behaviors relevant to anxiety and depression; as well as modulating receptors in the brain known to be involved in anxiety. The presence of the probiotics also reduced the stress-induced elevation in a hormone that regulates stress.

There is increasing evidence revolving around what is now being called the microbiome-gut-brain axis, suggesting an interaction between the good bacteria in your stomach and intestines, the gut, and the central nervous system. By modifying the gut microflora in mice, researchers were able to see reductions in responses to stress and anxiety; an extremely important finding considering the existing, known relationships between gastrointestinal disorders and stress-related psychiatric disorders.

Dr. John Cryan, Professor of Anatomy at University College Cork and one of the studies co-authors says that another crucial aspect of this study was to show that instead of working through immune or hormonal function, there was a direct neuronal route from the gut to the brain – a discovery that allows for specific therapies to be considered.

Researchers found that after a couple of weeks, mice on the probiotic diet were more relaxed than their placebo-treated counterparts; reduced levels of stress hormones and anxiety were recorded. Cryan says they even saw changes in the chemical make up of the brain. In fact, some of the reactions were so robust that they mimicked the reaction one could receive from an acute injection of Valium®.

So, should we be eating more probiotics rich foods? Dr. Cryan says it’s too early to take that leap. And while the research opens up a myriad of possibilities, fundamental studies are needed to back up any such potential claims about foods and their effects on the human brain.

“Caution is needed at this point as there will be differences between the actions of probiotic yogurts from strain to strain – even within the Lactobacillus family. The strain we used is not commercially or clinically available. What we have done is demonstrated that there is potential for bacteria-based food products to have marked effects on brain and behavior,” says Cryan.