Alterations of oral microbiota in young children with autism: Unraveling potential biomarkers for early detection.

Objectives: This study investigated the oral microbiota in young children with autism spectrum disorder (ASD) to determine possible alterations in microbial composition and identify potential biomarkers for early detection.

Methods: Dental plaque samples from 25 children with ASD (aged 3-6 years; M = 4.79, SD = 0.83) and 30 age- and sex-matched typically developing (TD) children were analyzed using 16S rRNA sequencing.

Results: The results showed lower bacterial diversity in children with ASD compared to controls, with distinct microbial compositions in the ASD and TD groups. Six discriminatory species (Microbacterium flavescens, Leptotrichia sp. HMT-212, Prevotella jejuni, Capnocytophaga leadbetteri, Leptotrichia sp. HMT-392, and Porphyromonas sp. HMT-278) were identified in the oral microbiota of ASD children, while five discriminatory species (Fusobacterium nucleatum subsp. polymorphum, Schaalia sp. HMT-180, Leptotrichia sp. HMT-498, Actinomyces gerencseriae, and Campylobacter concisus) were identified in TD controls. A model generated by random forest and leave-one-out cross-validation achieved an accuracy of 0.813. Receiver operating characteristic analysis yielded a sensitivity of 0.778, a specificity of 0.857, and an AUC (area under curve) of 0.937 (95 % CI: 0.82 - 1.00) for differentiating children with and without ASD.

Conclusion: The present study has unveiled significant disparities in the oral microbial composition between ASD and TD children.

Significance: These findings contribute to understanding the microbiome-brain connection in ASD and its implications for early detection and management. Further research is needed to validate these oral bacterial biomarkers and explore their mechanistic association with ASD pathophysiology.