Lactobacillus Role in Depression and Anxiety Prevention

Lactobacillus, a bacterium found in fermented foods and yogurt, has been discovered by researchers at the University of Virginia School of Medicine to assist the body regulate stress and may help avoid melancholy and anxiety. The discoveries pave the way for new treatments for anxiety, depression, and other mental-health issues.

“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 (BIG Center) and the TransUniversity Microbiome Initiative. “Our research could pave the way towards discovering much-needed therapeutics for anxiety and depression.”

The new study by UVA’s Alban Gaultier, PhD, and colleagues is noteworthy because it pinpoints the role of Lactobacillus, distinguishing it from all the other microbes that dwell in and on our bodies. These creatures are known collectively as the microbiota, and scientists are increasingly interested in targeting them to combat disease and improve overall health. UVA’s new discovery offers a significant step forward in that quest, giving scientists with an innovative new way to understanding the significance of particular microorganisms, which could aid in the creation of new therapies and cures for a wide range of mental and physical ailments.

The microbiota and depression

Numerous bacteria, fungi, and viruses live in our stomachs naturally. More microbes live in and on us than there are cells in our bodies. That may sound terrible, even frightening, but scientists are gradually realizing that these tiny organisms and their unending interactions are crucial to the health of our immune systems, mental health, and a variety of other aspects of our well-being. Microbiota disruptions, whether caused by sickness, bad food, or other factors, are known to contribute to numerous diseases and even cancer spread. As a result, researchers have been ecstatic in recent years about the potential to combat diseases by targeting the microbiome.

Early attempts to modify the gut flora with helpful bacteria known as probiotics yielded conflicting results. The sheer complexity of the microbiome has been a significant contributor to the problem. It’s believed that each of us has 39 trillion microorganisms, so trying to understand what specific bacteria or fungus do, let alone how they interact with all the other microbes and their host, can be like counting grains of sand on the beach.

Gaultier and his team used a novel way to zero down on Lactobacilli in particular. Previous study from Gaultier’s team revealed that the bacteria may alleviate depression in experimental mice, which was a tremendously hopeful discovery. However, the researchers needed to figure out 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 chose to continue their depression investigation using the Altered Schaedler Flora bacteria collection, which comprises two Lactobacillus strains and six other bacterial species. The researchers was able to generate mice with and without Lactobacillus using this rarely used bacterial community, avoiding the need for antibiotics.

The Altered Schaedler Flora did indeed produce fascinating outcomes. Gaultier and his colleagues were able to explain how Lactobacilli influence behavior and how a deficiency of the bacteria might exacerbate sadness and anxiety. Lactobacilli from the Lactobaccillacea family, they discovered, sustain levels of an immunological mediator called interferon gamma, which regulates the body’s response to stress and helps prevent depression.

With this knowledge, researchers will be able to create new methods for preventing and treating depression and other mental-health diseases in which Lactobacillus plays a major part. Patients suffering from (or at risk of) depression, for example, may one day benefit from specially made probiotic supplements that boost their levels of beneficial Lactobacillus.

With these results in hand, we have new tools to optimize the development of probiotics, which should speed up discoveries for novel therapies. 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.” 

Andrea R. Merchak, PhD, Researcher

Findings Published

The University of Virginia researchers published their findings in the journal Brain Behavior and Immunity. Merchak, Samuel Wachamo, Lucille C. Brown, Alisha Thakur, Brett Moreau, Ryan M. Brown, Courtney Rivet-Noor, Tula Raghavan, and Gaultier made up the research team. The researchers have no financial stake in the project.

The National Institutes of Health funded the research through funds T32 NS115657, T32 GM008136, F31 AI174782, T32 GM007267, and T32 GM148379, as well as the Owens Family Foundation, the Miller Family, the UVA TransUniversity Microbiome Initiative, and the UVA Presidential Fellowship in Neuroscience.

UVA’s TransUniversity Microbiome Initiative, or TUMI, acts as the University’s principal core for cutting-edge microbiome research. The effort aims to improve illness treatment and prevention by increasing our understanding of the microbiome.