Lactobacillusmaintains IFNγ homeostasis to promote behavioral stress resilience

Abstract

AbstractThe gut microbiome consists of the trillions of bacteria, fungi, and viruses that inhabit the digestive tract. These communities are sensitive to disruption from environmental exposures ranging from diet changes to illness. Disruption of the community of lactic acid producing bacteria,Lactobaccillacea, has been well documented in mood disorders and stress exposure. In fact, oral supplement with manyLactobacillusspecies can ameliorate these effects, preventing depression- and anxiety-like behavior. Here, for the first time, we utilize a gnotobiotic mouse colonized with the Altered Schaedler Flora to remove the two native species ofLactobaccillacea. Using this novel microbial community, we found that theLactobacillusspecies themselves, and not the disrupted microbial communities are protective from environmental stressors. Further, we determine thatLactobaccillaceaare maintaining homeostatic IFNγ levels which are mediating these behavioral and circuit level responses. By utilizing the Altered Schaedler Flora, we have gained new insight into how probiotics influence behavior and give novel methods to study potential therapies developed to treat mood disorders.