Gut bacteria affects the brain

Recent studies have suggested that the host's gut microbiota may affect the brain and behavior. A study's results showed that mice fed a broth containing Lactobacillus rhamnosus were less anxious than mice fed sterile broth. The bacteria-fortified mice also possessed a unique GABA receptor distribution profile in the brain as compared to that of sterile broth-fed mice. Interestingly, when they cut the vagus nerve in the mice fed bacteria, they returned to an anxious phenotype similar to that of their sterile broth-fed brethren. The vagus nerve may be an important pathway for inducing behavioral effects caused by gut bacteria.