While there are trillions of microbes in the gut microbiota, they are easily affected when exposed to various environmental influences. These are reflected in the behavior of one microbe, Lactobacillus (LB), in response to mood pathology and stressors. A new study in the journal Brain, Behavior, and Immunity extends these findings in a mouse model, showing that this organism protects against such disruption via its ability to maintain the levels of an important cytokine, interferon-gamma (IFNÎł), at physiologically normal levels.
Study: Lactobacillus from the Altered Schaedler Flora maintain IFNγ homeostasis to promote behavioral stress resilience. Image Credit: Elif Bayraktar / Shutterstock
Earlier research showed a close connection between the gut microbiota and the brain, spurring new studies into the effect of perturbations in the former on mental health. Dysbiosis has often been identified in patients under stress or with mood disorders, especially with respect to LB. Moreover, in both human and animal studies, this organism has been found to improve the individual’s mood and relieve anxiety while enhancing resistance to stress.
This so-called “psychobiotic” effect has been noted across various species and strains of LB, indicating that the organisms themselves are responsible for the observed benefit. However, certain findings suggest that some species, such as L. intestinalis and L. reuteri have detrimental effects on the host. Little is known about what would happen if LB were to be completely removed.
The Altered Schaedler Flora (ASF) refers to a gnotobiotic consortium or set of bacteria in which all members are well-known. Established in