The Gut-Microbiota-Brain Axis in Autism Spectrum Disorder

Abstract

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairments in social interactions/behaviors and increased ste-reotypical repetitive behavior. Gastrointestinal disorders, ranging from severe constipation to diarrhea, are particularly prevalent for people on the autism spectrum , which may relate to an underlying dysbiosis (breakdown or imbalance) in the gut microbial community. Many studies have also identified changes in the gut microbiome in ASD compared to neurotypical cohorts in animal models and human populations. Microbial probiotics to help revert these gut microbial changes have been tested in animal models of ASD. Some have shown reversal of ASD behaviors and modulating the integrity of the gastrointestinal epithelial barrier. The gut-microbiota-brain axis has been described as a multidirectional communication channel between the three systems: the gut, gut microbes, and the brain, but whether these gastrointestinal microbes play a role in the context of ASD and whether they can be harnessed as a target for gastrointestinal therapies in humans is yet to be determined.