Abstract
INTRODUCTION: To investigate the horizontal transmission of oral-gut microbiota in autism spectrum disorder (ASD) families and its potential implications for ASD pathogenesis. METHODS: The research employed a paired cohort design using family cohorts (23 ASD children/17 parents vs. 18 Non-ASD children/16 parents), conducting integrated microbiome and metabolomic analyses of oral and fecal samples. RESULTS: The findings revealed that ASD families exhibited significantly increased oral microbial species diversity alongside substantial alterations in gut microbiota composition, particularly demonstrating a lower Firmicutes/Bacteroidetes ratio (3.60/2.97) compared to Non-ASD families (5.59/5.35). Specific microbial changes included notable enrichment of Prevotella_9 in ASD gut microbiota. Metabolomic profiling identified significant disruptions in multiple metabolic pathways, including impaired L-rhamnose degradation and glutathione metabolism. The study observed coordinated oral-gut axis alterations through synchronized changes in Caulobacter and Serratia abundances, suggesting a distinct dysbiotic pattern along this microbial continuum. Additional metabolic findings demonstrated reduced levels of fecal glutamine and Ala-Gly in ASD children, with glycylproline exhibiting high predictive value for family typing (AUC = 0.91). Integrative analysis further revealed significant correlations between Holdemanella and various lipid metabolites. DISCUSSION: It indicates that ASD families display characteristic oral-gut microbiota interactions accompanied by metabolic abnormalities, potentially reflecting familial microbial transmission patterns that may contribute to ASD pathophysiology.