Gut microbiota linked to gastrointestinal symptoms in children with autism

A cross-sectional study in Pediatric Research examined associations between gastrointestinal symptoms, autism spectrum disorder (ASD) severity, intestinal biomarkers, and gut microbiota. Researchers analyzed baseline clinical trial data, including 72 children with ASD for biomarker testing and stool samples from 135 children, including typically developing controls and siblings, for microbiome analysis. Eligible children with ASD were aged 4–16 years. Assessments included a modified GI Severity Index (GSI), the Social Responsiveness Scale (SRS-2), plasma and fecal biomarkers, and 16S rRNA sequencing.

GSI and SRS-2 scores were significantly correlated (p=0.02), although the supplied results did not quantify the association’s magnitude. Neither score correlated with measured biomarkers: plasma zonulin, occludin, and S100A9, or fecal calprotectin. None of these biomarkers exceeded published normal values. Compared with typically developing children, children with ASD had reduced fecal microbial richness and differences in microbial composition, including increased relative abundance of Fusicatenibacter, Blautia, Sarcina, and Eubacterium. Those with ASD and GI symptoms had increased Bacteroides and Ruminococci.

The findings link microbial differences with GI symptoms without corresponding evidence of inflammation or increased permeability on the measured biomarkers. However, the cross-sectional design cannot establish causality or whether microbiome changes precede symptoms. Exclusion of children with existing GI conditions also limits generalizability. These associations do not establish a microbiome-directed treatment strategy.