A bowl of yoghurt daily may help boost mental health

New York: Yoghurt is not only good for your gut, but could lift your mood as well, according to a study.

Researchers at the University of Virginia School of Medicine have discovered how Lactobacillus, a bacterium found in fermented foods and yoghurt, helps the body manage stress and may help prevent depression and anxiety.

The study, published in the journal Brain, Behavior, and Immunity, opens the door to new therapies to treat anxiety, depression and other mental health conditions.

The discovery is notable because it pinpoints the role of Lactobacillus, separating it from all the other microorganisms that naturally live in and on our bodies, said Alban Gaultier, researcher at the varsity.

"Our discovery illuminates how gut-resident Lactobacillus influences mood disorders, by tuning the immune system," said Gaultier, from the varsity's Department of Neuroscience.

"Our research could pave the way toward discovering much-needed therapeutics for anxiety and depression."

The team took an innovative approach to focus on Lactobacilli in specific. Prior research from Gaultier's lab suggested that the bacteria could reverse depression in lab mice -- a hugely promising finding.

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 team decided to continue their depression research using a collection of bacteria, known as "Altered Schaedler Flora," which includes two strains of Lactobacillus and six other bacterial strains.

With this rarely used bacterial community, the team was able to create mice both with and without Lactobacillus, circumventing the need for antibiotics.

The results explain exactly how Lactobacilli influences behaviour, and how a lack of the bacteria can worsen depression and anxiety.

Lactobacilli in the family Lactobaccillacea 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 optimise the development of probiotics, which should speed up discoveries for novel therapies," researcher Andrea R. Merchak said.

"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."