Children with autism spectrum disorder may have reduced fecal microbial diversity

1. In this cross-sectional study, stool samples from children with Autism Spectrum Disorder (ASD) and increased GI symptoms yielded reduced microbiome diversity compared to stool samples from typically developing children.

Evidence Rating Level: 2 (Good)

Many children with Autism Spectrum Disorder (ASD) suffer from increased gastrointestinal (GI) symptoms, with 31-84% of those with ASD suffering from severe symptoms including increased abdominal pain, food selectivity, constipation, diarrhea, stool incontinence, and vomiting. One possible mechanism to explain increased GI symptoms in patients with ASD is gut dysbiosis and subsequent overgrowth of core flora, including Bacteroides and Ruminococci. This cross-sectional study compared stool samples from children aged 4-16 with ASD to neurotypical children or siblings. It was found that children with ASD, both with or without GI symptoms, had a statistically significantly lower level of polymicrobial diversity compared to siblings (p=0.01) or neurotypical children (p=0.06). Children with ASD and GI symptoms had a higher abundance of Bacteroides and Ruminococcus flora, which was positively correlated with higher rates of flatulence, nighttime awakening, abdominal pain, and foul-smelling stool. Overall, this study demonstrates that children with ASD have less fecal microbial diversity compared to siblings and neurotypical children, correlating with a higher severity of GI symptoms. Knowing that children with ASD may struggle with food selectivity, medication adherence, and nutrition, further research is necessary to maximize positive outcomes.

Click here to read this study in Pediatric Research

Citation: Harne V, Fatheree NY, Serrano AV, Okeugo B, Fadhel Alvarez A, Hessabi M, et al. Gut microbiota are linked to gastrointestinal symptoms and behavioral changes but not inflammation in autism spectrum disorder: a cross-sectional analysis. Pediatr Res. 2026 Oct 14. doi: 10.1038/s41390-026-05548-6. Epub ahead of print. PMID: 42875511.

© 2026 2 Minute Medicine, Inc. All rights reserved. No part of this article may be reproduced, distributed or transmitted in any form or by any means without the prior written permission of 2 Minute Medicine, Inc. To license this content, contact 2 Minute Medicine, Inc. This article is for informational and educational purposes only; it is not medical advice and does not replace the judgment of a qualified healthcare professional.
Image: © 2 Minute Medicine