The Gut Microbiota and Autism Spectrum Disorder: Current Research and Therapeutic Insights

Autism Spectrum Disorder (ASD) is a collective term for neurodevelopmental disorders with core features of social communication impairment, restricted and repetitive behaviors, and narrow interests. These include classic autism, Asperger's syndrome, and pervasive developmental disorder not otherwise specified. ASD is currently managed with behavioral interventions, rehabilitation training, and family support, but there is no curative medication. Recent studies suggest that some patients with ASD may experience gastrointestinal symptoms. Perhaps this is associated with the disturbances of gut microbiota. Increasing evidence has demonstrated that the composition of gut microbiota in ASD individuals is different from that in normal population and may be associated with neurodevelopmental processes via the gut-brain axis. This article reviews the evidence for the association between gut microbiota and ASD, describes the characteristics of microbial changes, and analyzes the mechanism by which changes in the composition of the microbiota affect the occurrence and development of ASD. Finally, we review recent advances in microbiota-targeted therapeutic strategies, including probiotics, prebiotics, and fecal microbiota transplantation, which provide new approaches to alleviate and improve autism-related symptoms and point out the future research direction.