Critical Appraisal of Systematic Reviews Assessing Gut Microbiota and Effect of Probiotic Supplementation in Children with ASD-An Umbrella Review.

Given the significance of gut microbiota in autism spectrum disorder (ASD), we aimed to assess the quality of systematic reviews (SRs) of studies assessing gut microbiota and effects of probiotic supplementation in children with ASD. PubMed, EMBASE, PsycINFO, Medline, and Cochrane databases were searched from inception to November 2024. We included SRs of randomised or non-randomized studies reporting on gut microbiota or effects of probiotics in children with ASD. A total of 48 SRs (probiotics: 21, gut microbiota: 27) were included. The median (IQR) number of studies and participants was 7 (5) and 328 (362), respectively, for SRs of probiotic intervention studies and 18 (18) and 1083 (1201), respectively, for SRs of gut microbiota studies in children with ASD. The quality of included SRs was low (probiotics: 12, gut microbiota: 14) to critically low (probiotics: 9, gut microbiota: 13) due to lack of reporting of critical items including prior registration, deviation from protocol, and risk of bias assessment of included studies. Assuring robust methodology and reporting of future studies is important for generating robust evidence in this field.