Crowdsourced study of children with autism and their typically developing siblings identifies differences in taxonomic and predicted function for stool-associated microbes using exact sequence variant analysis.

Autism Spectrum Disorder ( ASD) affects 1 in 59 children in the United States and is impacted by both genetic and environmental factors, including the gut microbiome. To investigate the link between microbiomefunctionality and ASD, this study analyzes behavioral data (with home video and questionnaires) and 16S- ampliconscrowd-sourced from age-matched sibling pairs (2-7 yo) where one sibling has an ASDdiagnosis and the other does not. We identified 21 exact sequencevariants (ESVs) that are significantly differentially abundant between the two cohorts. ESVs from the families Ruminococcaceaeand Bacteroidaceaewere found preferentially in the ASD cohort, while ESVs from the genera Bifidobacterium, Porphyromonas, Slackia, Desulfovibrio, species Acinetobacter johnsonii, and the Lachnospiraceaefamily, were specific to the neurotypical cohort. Predicting KEGGOrthologs from these ESVs, we found both cohortsharbor butyragenic pathways, but the ESVs enriched in the ASD cohortcan use 4-aminobutanoate as precursor, potentially impacting the availability of neurotransmitters.