The Microbiota in the Diagnosis and Treatment of Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition characterized by impaired social interaction, communication deficits, and repetitive behaviors. Recent research highlights the role of the gut microbiota in ASD pathophysiology, particularly through the microbiota–gut–brain axis. The microbiota may influence neurodevelopment via multiple signaling pathways, including the GABAergic and serotonergic systems, as well as the mTOR signaling pathway. This analytical review examines current evidence on microbiota alterations in ASD and evaluates microbiota-targeted strategies for diagnosis and treatment, focusing on fecal microbiota transplantation (FMT), probiotics, and diet-based therapeutic approaches. The review also provides a critical appraisal of the microbiota–gut–brain axis in the context of autism spectrum disorder.