A cross-disciplinary research team from the Faculty of Dentistry and the Department of Psychology of the University of Hong Kong (HKU) has found a promising connection between oral microbiota and autism spectrum disorder (ASD). Their study, published in the Journal of Dentistry, introduces a prediction model with an 81% accuracy rate for identifying children with autism through simple oral sampling.

ASD is a lifelong neurodevelopmental condition characterized by social communication difficulties, as well as restricted and repetitive behaviors and interests. ASD has emerged as a critical global public health challenge, with prevalence rates steadily rising—affecting 1 in 36 children in the United States and approximately 1 in 49 children in Hong Kong’s educational system.

Early identification and intervention for ASD is crucial, yet diagnosis typically occurs around age 5, with milder cases often identified when social demands exceed capabilities. Current screening methods rely heavily on subjective observations by teachers and caregivers, with accuracy varying based on the observer’s understanding of ASD.

Emerging research highlights microbiome biomarkers as promising, objective screening tools that could complement existing methods, improving early detection and enabling timely intervention during critical developmental stages.

Prior studies suggest the gut and oral microbiome play key roles in inflammation, immune dysfunction, and gut-brain axis disruption, all linked to ASD. Since digestion starts in the mouth, analyzing oral bacteria could aid early autism identification. While gut microbiota’s connection to autism has been explored, research on oral microbiota remains limited.

In view of this, a cross-disciplinary research team combining the expertise of Professor Cynthia Kar Yung Yiu, Associate Professor Rory Munro Watt from the HKU Faculty of Dentistry, along with Dr. Charles Cheuk-fung Hau and Senior Technical Officer Mr. Raymond Wai-man Tong, together with Senior Lecturer and Ph.D. candidate Jacqueline Wai-yan Tang and Associate Professor Kathy Kar-man Shum from the Department of Psychology was formed to explore the differences in oral microbiota between children with ASD and neurotypical children.

The research team examined oral bacterial samples from 25 children with autism and 30 neurotypical children aged 3–6. Their analysis revealed significant differences in bacterial communities, with 11 specific bacterial species showing particularly strong potential as biomarkers for ASD.

Based on the findings, the team developed a prediction model with an 81% accuracy rate for identifying children with autism. This innovation paves the way for a simple, non-invasive screening tool that could be integrated into routine dental check-ups for children, enabling early referral for professional evaluation.

This collaboration provides a promising foundation for developing practical, non-invasive screening tools to complement existing methods. The team envisions a future where a quick oral swab during regular dental visits could help identify children who would benefit from early intervention, when therapy is most effective. The next phase of the study will expand the sample size to further validate and refine this innovative technology, with the ultimate goal of making it widely accessible.