UVA researchers find unlikely source that may help people with stress, depression, anxiety

Researchers have found an unlikely source to help the body manage stress, and it also may help prevent depression and anxiety.

University of Virginia School of Medicine researchers have discovered Lactobacillus, a bacterium found in fermented foods and yogurt, may improve our health.

The findings open the door to new therapies to treat anxiety, depression and other mental-health conditions.

The UVA scientists have published their findings in the journal Brain Behavior and Immunity.

The new research from UVA’s Alban Gaultier, PhD, and collaborators is notable because it pinpoints the role of Lactobacillus, separating it out from all the other microorganisms that naturally live in and on our bodies.

“Our discovery illuminates how gut-resident Lactobacillus influences mood disorders, by tuning the immune system,” said Gaultier, of UVA’s Department of Neuroscience, the Center for Brain Immunology and Glia and the TransUniversity Microbiome Initiative. “Our research could pave the way towards discovering much-needed therapeutics for anxiety and depression.”

Early attempts to manipulate the gut flora with beneficial bacteria, called probiotics, have produced mixed results.

Gaultier and his team took an innovative approach to hone in on Lactobacilli. Prior research from Gaultier’s lab suggested that the bacteria could reverse depression in lab mice, but the researchers needed to understand how.

“We were aware from our prior research that Lactobacillus was beneficial in improving mood disorders and was lost following psychological stress, but the underlying reasons remained unclear, primarily due to the technical challenges associated with studying the microbiome.”

Gaultier and his colleagues were able to explain exactly how Lactobacilli influence behavior, and how a lack of the bacteria can worsen depression and anxiety.

Lactobacilli in the family Lactobaccillacea, they found, maintain the levels of an immune mediator called interferon gamma that regulates the body’s response to stress and helps stave off depression.

Armed with this information, researchers may develop new ways to prevent and treat depression and other mental-health conditions in which Lactobacillus plays an important role.

For example, patients struggling with depression might take specially formulated probiotic supplements that will optimize their levels of helpful Lactobacillus.

“With these results in hand, we have new tools to optimize the development of probiotics, which should speed up discoveries for novel therapies,” said researcher Andrea R. Merchak, PhD. “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 and depression.”