Researchers from the University of Virginia School of Medicine have made a groundbreaking discovery on how the bacterium Lactobacillus, commonly found in fermented foods and yogurt, aids the body in managing stress and may serve as a preventive measure against depression and anxiety.
The study, published in the journal Brain, Behaviour, and Immunity, unveils a new avenue for potential therapies targeting mental health conditions. Lead researcher Alban Gaultier and his collaborators have identified the specific role of Lactobacillus, differentiating it from the myriad of microorganisms constituting the human microbiota.
The microbiota, comprising bacteria, fungi, and viruses, has become a focal point in scientific efforts to combat diseases and enhance overall health. This study marks a significant advancement, offering a fresh perspective on individual microbes and their potential to develop treatments for various mental and physical ailments.Â
Gaultier, from UVA’s Department of Neuroscience, highlights the significance of the findings, stating, “Our discovery illuminates how gut-resident Lactobacillus influences mood disorders, by tuning the immune system,” and expresses optimism about the potential development of therapeutics for anxiety and depression.Â
The human gut is a complex ecosystem hosting numerous microorganisms crucial to immune systems, overall health, and mental well-being. Disruptions in the microbiota have been linked to various diseases, prompting researchers to explore therapeutic interventions targeting these microorganisms.Â
Previous research by Gaultier’s lab demonstrated that Lactobacillus could reverse depression in lab mice, prompting further investigation into the mechanisms behind this phenomenon. The researchers focused on a collection of bacteria known as “Altered Schaedler Flora,” including Lactobacillus strains, to understand how these bacteria influence behaviour.Â
The results revealed that Lactobacilli in the Lactobaccillacea family play a key role in maintaining levels of interferon gamma, an immune mediator that regulates the body’s response to stress and helps prevent depression. The absence of these bacteria was linked to an exacerbation of depression and anxiety.Â
The researchers overcame technical challenges associated with studying the microbiome by using the Altered Schaedler Flora, providing valuable insights into the specific contributions of Lactobacillus. Armed with this knowledge, the researchers anticipate the development of new approaches to prevent and treat depression and other mental health conditions by optimizing levels of beneficial Lactobacillus.
This could involve the use of specially formulated probiotic supplements tailored to enhance Lactobacillus levels in individuals struggling with or at risk for depression. Researcher Andrea R. Merchak emphasized the significance of the findings, stating, “With these results in hand, we have new tools to optimize the development of probiotics, which should speed up discoveries for novel therapies.”
The team is eager to explore how maintaining a healthy level of Lactobacillus and interferon gamma could be investigated further for preventing and treating anxiety and depression. The research team included Andrea R. Merchak, Samuel Wachamo, Lucille C. Brown, Alisha Thakur, Brett Moreau, Ryan M. Brown, Courtney Rivet-Noor, Tula Raghavan, and Gaultier. Â
Journal Reference Â
Andrea R. Merchak et al, Lactobacillus from the Altered Schaedler Flora maintain IFNÎł homeostasis to promote behavioural stress resilience, Brain, Behaviour, and Immunity (2023). DOI: 10.1016/j.bbi.2023.11.001.Â
