In this study, we investigated how gut microbiota is linked to social behavior and metabolic health. We compared Dominant and Submissive mice and evaluated their gut microbiome, body weight, adipose tissue, inflammation-related markers, and social behavior.

We found that Submissive mice had a less diverse gut microbiome, lower body weight, reduced adipose tissue mass, smaller adipocytes, and higher inflammatory markers in adipose tissue. We also examined the direct role of gut microbiota by transferring microbiota from Dominant or Submissive mice into germ-free mice. The transplanted mice developed behavioral and physiological traits similar to the donor group.

These findings suggest that the gut microbiota plays an important role in shaping social behavior, metabolism, and inflammation through the gut–brain axis.