A Meta-Analysis of the Effects of Gut Microbiota-Based Interventions on Gastrointestinal and Behavioral Symptoms in Children With Autism Spectrum Disorder

CONTEXT: Despite an increasing body of research showing gut microbiota-based interventions can improve gastrointestinal (GI) symptoms and behavioral symptoms in both humans and animals, there are still disagreements about its impact on autism spectrum disorder (ASD) in children. OBJECTIVE: The goal of this systematic review and meta-analysis was to fully investigate the effects of gut microbiota-based interventions (eg, fecal microbiota transplantation, probiotics, prebiotics) on GI and behavioral symptoms in children with ASD. DATA SOURCES: The PubMed, Web of Science, the Cochrane Library, China National Knowledge Infrastructure, and Scopus databases were searched from inception to August 25, 2024. DATA EXTRACTION: Data were extracted by 2 reviewers independently, and discrepancies in authors' judgments were resolved by discussion or consulting a third author. DATA ANALYSIS: The scale score of GI and behavioral symptoms before and after the intervention was extracted from included trials to evaluate the therapeutic effects of gut microbiota-based therapy in children with autism. RESULTS: A total of 5722 records were identified, of which 13 included in narrative synthesis and 8 studies included a meta-analysis. The nonsignificant overall effect size of gut microbiota-based intervention on GI symptoms (standardized mean difference [SMD] = -0.34 [95% CI, -0.76 to 0.07]; P = .11) and behavioral symptoms (SMD = -0.18 [95% CI, -0.37 to 0.02]; P = .08) was observed. Nevertheless, we observed a significant effect size on behavioral symptoms in the subgroup of the intervention duration (SMD = -0.26 [95% CI, -0.49 to -0.03]; P = .02). CONCLUSIONS: In children with autism, the proof supporting the validity of gut microbiota-based intervention on GI and behavioral symptoms should be interpreted cautiously. More randomized controlled trials with rigorous methodological quality are required to precisely confirm the curative benefits of gut microbiota-based interventions on GI and behavioral symptoms in children with autism. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD42024583213.