Chronic stress may cause gut bacteria imbalance and brain inflammation linked to depression

Chronic unpredictable mild stress in male mice resulted in significant behavioral depression-like symptoms and disrupted gut microbiota.

• Behavioral assessments indicated pronounced depression-like behaviors in mice subjected to chronic unpredictable mild stress.
• Probiotic treatment significantly alleviated depression-like behaviors in stressed mice.
• Chronic stress reduced gut microbial diversity and increased the Firmicutes/Bacteroidetes ratio while decreasing beneficial bacteria.
• Probiotic supplementation restored gut microbiota alterations to levels similar to control mice.
• Chronic stress compromised intestinal barrier function, evidenced by reduced levels of proteins ZO-1 and Occludin, which were partially reversed by probiotics.
• Increased levels of pro-inflammatory cytokines and microglial activation markers were observed in the brains of stressed mice, which were suppressed by probiotic intervention.

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