Impact of Sex, Gonadectomy, and Repeated Restraint Stress on Gut Microbiome in Mice

Recently, the bidirectional connection between the gastrointestinal microbiota and the brain has gained interest in many research studies. Findings have highlighted the potential role of stress and sex hormones in modulating the gut microbiome. To our knowledge, no study has investigated the effect of sex hormone perturbations on the gut microbiota in response to stress. To understand how stress may alter the gut microbiota differently depending on sex, gonadectomized and sham-operated male and female mice were subjected to 2 h of daily restraint stress for seven consecutive days. Body weight and plasma level of corticosterone were evaluated. Bacterial diversity and composition of colon and cecum were analyzed by sequencing of 16S rRNA gene. The bacterial communities were strongly altered by stress in the colon than in the cecum. A profound dysregulation of several metabolic and functional pathways was observed in sham mice. Alterations in the gut microbiome diversity and its functional pathways due to stress were more pronounced in males than in females. The present results provide potential sex-specific biomarkers and novel metabolic signatures in the gut microbiota related to stress disorders which may be used as potential targets in diagnostic and therapeutic approaches in neurogastroenterological diseases.