The combination of living Bifidobacterium, Lactobacillus, and Streptococcus improves social ranking and relieves anxiety-like behaviors in competitive mice in a social dominance tube test

Introduction Social rank has a profound influence on the behavior and health of humans and animals. Methods To explore the effect of a combination of living Bifidobacterium, Lactobacillus and Streptococcus (CLB) on anxiety- and depression-like behaviors and social rank, mice were subjected to a social dominance tube test (SDTT). The behaviors, rank, gut microbiota, and expression of inflammatory cytokines and brain-derived neurotrophic factor (BDNF) in the hippocampus were measured. Results The results indicated that CLB improved the SDTT ranking score of the losers and alleviated anxiety-like behaviors of the winners. CLB decreased the level of Desulfovibrio and augmented the level of Mollicutes in the feces, increased BDNF content, and reduced the level of tumor necrosis factor-alpha in the hippocampus. Conclusion These findings indicated that CLB may be used for the treatment of anxiety and improvement of the rank score via regulation of gut microbiota and anti-inflammatory effects.