Abstract
OBJECTIVE: Although Caries Risk Assessment (CRA) tools are widely recognised in preventive dentistry for predicting dental caries risk in children, there is a notable lack of studies addressing CRA within the Chinese population. This study aimed to evaluate the biological validity of the modified caries-risk assessment tool for preschool children (PSC-MCAT) by analysing the oral microbiome of children stratified by caries risk. MATERIALS AND METHODS: A comprehensive analysis of the oral microbiome was conducted on 72 preschool children categorised into low- (L), moderate- (M), and high-risk (H) groups based on the PSC-MCAT criteria. Next-generation sequencing was employed to assess microbial diversity and structure. Statistical analyses were performed to identify significant differences among the risk groups. RESULTS: The analysis revealed statistically significant differences in microbial diversity and structure among the caries risk groups (P < .05). Specific caries risk biomarkers, including Scardovia, Prevotella, and Megasphaera, were significantly enriched in the H group (P < .05). Co-occurrence network analysis showed that the M group exhibited a more complex microbial network compared to the H group, while the L group displayed sparse ecological interactions. KEGG pathway analysis identified 8 differentially abundant metabolic pathways among the risk groups. Furthermore, certain biomarkers in the H group, such as Scardovia and Megasphaera, were associated with D-arginine and D-ornithine metabolic pathways (P < .05) and were closely linked to children's oral health behaviours, including sweet food intake frequency and regular fluoride application (P < .05). CONCLUSION: This study provides the first biological validation of the PSC-MCAT's risk stratification capacity, establishing a mechanistic link between clinical risk tiers and the dynamics of acidogenic pathobionts as well as host-microbe metabolic interactions. These findings offer valuable insights for prognostic predictions and targeted caries management strategies.