Oral Microbiota May Serve as Early Screening Tool for Autism Spectrum Disorder

A collaborative research initiative involving experts from the Faculty of Dentistry and the Department of Psychology at the University of Hong Kong (HKU) has identified a significant correlation between oral microbiota and autism spectrum disorder (ASD). Their findings, published in the Journal of Dentistry, present a groundbreaking prediction model that boasts an accuracy rate of 81% in diagnosing children with autism through simple oral samples.

ASD is a complex neurodevelopmental condition marked by challenges in social communication, alongside restricted and repetitive behaviors. The condition represents a pressing public health issue globally, with rates of occurrence rising steadily; it currently affects approximately 1 in 36 children in the United States and about 1 in 49 children within Hong Kong's education system.

Early diagnosis and intervention for ASD are vital, but traditional methods typically yield results around the age of five, often identifying milder cases only when social pressures exceed the child's capabilities. The reliance on subjective observations from educators and caregivers can lead to variability in diagnostic accuracy, largely dependent on the observer's understanding of ASD.

Recent studies suggest that microbiome biomarkers could provide objective screening alternatives, enhancing early detection and facilitating timely intervention during critical developmental phases. Research indicates that both gut and oral microbiomes are integral to processes involving inflammation, immune response, and the gut-brain axis, all of which are related to ASD. Given that digestion initiates in the mouth, analyzing oral bacteria may offer insights for early autism identification. While the link between gut microbiota and autism has been explored, research focusing on oral microbiota remains relatively scarce.

To address this knowledge gap, the interdisciplinary research team, led by Professor Cynthia Kar Yung Yiu and Associate Professor Rory Munro Watt from the Faculty of Dentistry, along with Dr. Charles Cheuk-fung Hau, Senior Technical Officer Mr. Raymond Wai-man Tong, Senior Lecturer and Ph.D. candidate Jacqueline Wai-yan Tang, and Associate Professor Kathy Kar-man Shum from the Department of Psychology, investigated the oral microbiota differences between children diagnosed with ASD and their neurotypical peers.

The study involved the analysis of oral bacterial samples from 25 children with autism and 30 neurotypical children aged between three and six years. The results indicated notable disparities in bacterial communities, with 11 specific bacterial species emerging as strong potential biomarkers for ASD. This innovative research culminated in the development of a predictive model that accurately identifies autism in children, paving the way for a non-invasive screening method that could be seamlessly integrated into routine dental examinations for children.

The collaboration lays a promising groundwork for creating practical screening tools that can supplement existing diagnostic methods. Researchers envision a future where a quick oral swab taken during regular dental visits can help identify children who may benefit from early intervention, which is most effective when initiated at a young age. Future phases of the study will focus on expanding the sample size to validate and refine this innovative approach, with the ultimate objective of making it widely accessible.