Microbiota-targeted interventions in Autism Spectrum Disorder: A Scoping Review

The gut–microbiota–brain axis has emerged as a promising target for personalized interventions in Autism Spectrum Disorder (ASD) through supplementation with probiotics, postbiotics, prebiotics, and synbiotics. However, evidences from supplementation studies in ASD remains inconclusive regarding the optimal selection of microbe-derived compounds and strain-specific effects across distinct functional and behavioral domains. To comprehensively map the available literature on microbiota-targeted supplementation in ASD, describing the types and formulations of compounds investigated across distinct domains (gastrointestinal symptoms, behaviors, sleep, and neurophysiological functioning), and, where reported, summarizing strain-specific use and the proposed gut–brain mechanisms associated with these outcomes. A comprehensive scoping review was conducted, including clinical trials and randomized clinical trials (RCTs) published between 2013 and 2025 on individuals with a formal diagnosis of ASD. A total of 28 eligible articles were identified, of which 13 were ultimately included. Among these, 10 involved probiotics, 1 prebiotics, and 2 synbiotics. No studies investigated postbiotic supplementation as intervention strategy. The findings support the clinical utility of the gut-microbiota-brain axis as a modulatory pathway in ASD, highlighting preliminary associations with gastrointestinal and behavioral outcomes. However, translation into clinical pratice is currently limited by the lack in generalizability due to the heterogeneity of ASD phenotypes. Future trials integrating multi-omics approaches with biological stratification, clinical data, and neurophysiological measures may help clarify the underlying mechanisms and inform the development of personalized interventions in ASD.