The impact of gut microbiota on brain and behaviour: implications for psychiatry

Purpose of review The gut microbiota has become a focus of research for those interested in the brain and behaviour. Here, we profile the gut microbiota in a variety of neuropsychiatric syndromes. Recent findings Multiple routes of communication between the gut and brain have been established and these include the vagus nerve, immune system, short chain fatty acids and tryptophan. Developmentally, those born by caesarean section have a distinctly different microbiota in early life to those born per vaginum. At the other extreme, individuals who age with considerable ill-heath tend to show narrowing in microbial diversity. Recently, the gut microbiota has been profiled in a variety of conditions including autism, major depression and Parkinson's disease. There is still debate as to whether or not these changes are core to the pathophysiology or merely epiphenomenal. Summary The current narrative suggests that certain neuropsychiatric disorders might be treated by targeting the microbiota either by microbiota transplantation, antibiotics or psychobiotics.