The Influence of Gut Bacteria on Anxiety Behaviors in Rodents: Implication for Mental Health in Humans

Summary:  View help for Summary Using an animal paradigm, with rodents, we investigated whether a probiotic formulation—containing two strains of bifidobacteria and lactobacilli—might have anxiety-reducing effects. We administered the probiotic to an experimental group of rats (n = 10), which we compared to a placebo control group of rats (n = 10) to evaluate differences in anxiety behaviors. We assessed the animals’ anxiety behaviors using the Elevated Plus Maze (EPM) test and a fecal count on the EPM. More entries and a greater length of time on the open arms of the EPM, as well as fewer fecal pellets, reflect less anxiety. We ran an independent samples t-test and Poisson regression analyses to compare means between groups for anxiety behaviors. Our results indicate that the probiotics had anxiety-reducing effects, with statistical significance. This research supports evidence of a connection between certain gut bacteria and mental health, and it adds to the catalog of bacteria that could potentially improve mental health.