Stress transmission, stress buffering, and the role of gut microbiota in cohabiting mice

Prior research has demonstrated that stress can be transmitted from one individual to another, while the underlying mechanisms of this transmission remain elusive. This study concentrated on the phenomena of stress transmission and stress buffering in cohabitation settings, aiming to elucidate its mechanisms. It was found that healthy mice cohabiting with depressed mice displayed altered behaviors, including increased resting time in the tail suspension test, decreased time in the center area in the open-field test, and reduced food intake and prolonged feeding latency in the novelty-suppressed feeding test. Moreover, they exhibited hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis, elevated levels of inflammatory factors, increased intestinal permeability, and decreased brain-derived neurotrophic factor (BDNF) expression level in the hippocampus. The depressive symptoms of depressed mice cohabiting with healthy mice were improved accordingly. The analysis of gut microbiota revealed that cohabitation led to an interaction between the gut microbiota of healthy mice and depressed mice, and the phenomenon of gut microbiota transmission occurred. Further correlation analysis between gut microbiota and physiological index indicated that the transmission of specific gut microbiota was associated with stress transmission and stress buffering, and Rikenellaceae_RC9_gut_group, Prevotellaceae-UCG-001, Odoribacter, and Ligilactobacillus might play a notable role in the gut microbiota communication.