Researchers from the University of Virginia School of Medicine have discovered a potential novel treatment for depression and anxiety. The scientists found that the common bacterium, Lactobacillus, found in fermented foods and yogurt plays a crucial role in managing stress.

According to Study Finds, specially formulated probiotic supplements that optimize the levels of this bacterium in patients may be the key in treating patients at risk for mental health disorders.

“Our discovery illuminates how gut-resident Lactobacillus influences mood disorders, by tuning the immune system,” said Alban Gaultier, Ph.D., one of the UVA investigators, in a university news release. “Our research could pave the way towards discovering much-needed therapeutics for anxiety and depression.”

Lactobacillus is one of the 39 trillion microorganisms that live in and on our bodies. These microorganisms are collectively known as microbiota, and scientists have increasingly sought to target them in finding ways to battle disease and improve our health. Disruption in the microbiota, whether from illness, poor diet, or other causes, contributes to many diseases and even helps spread cancer.

To isolate one of these microorganisms was a challenge to Gaultier and his team. The scientist had already noted in previous research that Lactobacillus was beneficial in improving mood disorders in mice and was lost during periods of psychological stress, but the reason why this occurred was unclear.

By using a collection of bacteria called Altered Schaedler Flora, which includes two strains of Lactobacillus and six other bacterial strains, they were able to create mice both with and without Lactobacillus.

The team found that Lactobacilli maintain the levels of an immune mediator called interferon gamma that regulates the body’s response to stress and helps stave off depression.

“With these results in hand, we have new tools to optimize the development of probiotics, which should speed up discoveries for novel therapies,” said fellow researcher Andrea R. Merchak, Ph.D. “Most importantly, we can now explore how maintaining a healthy level of Lactobacillus and/or interferon gamma could be investigated to prevent and treat anxiety.”  

The study was published in the journal Brain, Behavior, and Immunity.