Lactobacillus mucosae and Bifidobacterium longum Synergistically Alleviate Immobilization Stress-Induced Anxiety/Depression in Mice by Suppressing Gut Dysbiosis

Abstract

We isolated Lactobacillus mucosae NK41 and Bifidobacterium longum NK46 from human feces, which induced BDNF expression in corticosterone-stimulated SH-SY5Y cells, and examined their anti-depressive effects in mice. NK41, NK46, and their (1:1) mixture significantly mitigated immobilization stress (IS)-induced anxiety-like/depressive behaviors, hippocampal NF-κB activation, BDNF expression, Iba1⁺ cell population, and blood corticosterone, TNF-α, IL- 6, and lipopolysaccharide levels. Furthermore, they inhibited colitis marker NF-κB activation, and TNF-α expression in mice with IS-induced anxiety/depression. They additionally suppressed gut Proteobacteria and Bacteroidetes populations and bacterial lipopolysaccharide production. These findings suggest that NK41 and NK46 may alleviate anxiety/depression and colitis by suppressing gut dysbiosis.

Keywords: Bifidobacterium longum; Lactobacillus mucosae; anxiety; depression; gut microbiota.