Role of the Gut Microbiome in Autism Spectrum Disorders

Abstract

Autism spectrum disorder (ASD) is a severe neurodevelopmental or neuropsychiatric disorder with elusive etiology and obscure pathophysiology. Cognitive inabilities, impaired communication, repetitive behavior pattern, and restricted social interaction and communication lead to a debilitating situation in autism. The pattern of co-occurrence of medical comorbidities is most intriguing in autism, compared to any other neurodevelopmental disorders. They have an elevated comorbidity burden among which most frequently are seizures, psychiatric illness, and gastrointestinal disorders. The gut microbiota is believed to play a pivotal role in human health and disease through involvement in physiological homoeostasis, immunological development, glutathione metabolism, amino acid metabolism, etc., which in a reasonable way explain the role of gut-brain axis in autism. Branded as a neurodevelopmental disorder with psychiatric impairment and often misclassified as a mental disorder, many experts in the field think that a therapeutic solution to autism is unlikely to emerge. As the pathophysiology is still elusive, taking into account of the various symptoms that are concurrent in autism is important. Gastrointestinal problems that are seen associated with most of the autism cases suggest that it is not just a psychiatric disorder as many claim but have a physiological base, and alleviating the gastrointestinal problems could help alleviating the symptoms by bringing out the much needed overall improvement in the affected victims. A gut disorder akin to Crohn’s disease is, sometimes, reported in autistic children, an extremely painful gastrointestinal disease which is named as autistic enterocolitis. This disturbed situation hypothesized to be initiated by dysbiosis or microbial imbalance could in turn perturb the coordination of microbiota-gut-brain axis which is important in human mental health as goes the popular dictum: “fix your gut, fix your brain.”.