Microbiome, Anxiety & Depression (2011)
This study investigated the microbiome, anxiety & depression. It is understood that there is constant communication between the gut and the brain (the gut-brain axis). In this study, mice were fed a strain of probiotic (gut bacteria) or placebo. The mice who received the probiotics showed significantly fewer stress, anxiety and depression-related behaviours than the unsupplemented mice (controls). Not only was their behaviour different, but their levels of stress hormones were lower too. The researchers also observed altered GABA activity in the brains of the supplemented mice, suggesting a direct effect on brain chemistry.
Bravo JA, Forsythe P, Chew MV, Escaravage E, Savignac HM, Dinan TG, Bienenstock J, Cryan JF. (2011) Ingestion of Lactobacillus strain regulates emotional behavior and central GABA receptor expression in a mouse via the vagus nerve. Proc Natl Acad Sci U S A. Aug 29. [Epub ahead of print]