Salivary microbiome diversity in Chinese children with various caries states.

Objective: This study aimed to explore oral microbiome diversity among children with various caries status based on dmft scores.

Methods: A total of 320 children aged 3-5 years were recruited, with 66 healthy children and 254 children affected by dental caries. According to dmft scores, these children with dental caries were classified as "mild group" (dmft score 1-3), "moderate group" (dmft score 4-6), and "severe group" (dmft score 7-14). Healthy children with dmft score of 0 served as control group. Illumina MiSeq sequencing was employed to analyze all salivary samples collected from these children.

Results: The salivary microbial diversity among four groups was similar (p > 0.05). A total of five bacterial genera were highly abundant in the control group including Bergeyella, Acidimicrobiales, Acidimicrobiia, Halomonas, and Blautia (p < 0.05). For mild group, there were nine bacterial genera identified to be predominant: Porphyromonadaceae, Porphyromonas, Enterobacteriales, Enterobacteriaceae, Weissella, Leuconostocaceae, Alphaproteobacteria, Stenotrophomonas, and Rhizobiales (p < 0.05). Only one genus, Aggregatibacter was predominant in moderate group (p < 0.05). There were six bacterial genera (Alistipes, Lachnoclostridium, Escherichia-Shigella, Romboutsia, Sphingomonadales, and Denitratisoma) enriched in severe group (p < 0.05).

Conclusion: Oral microbial profile was different in children with various caries status based on dmft scores.

Clinical Relevance: The results might be beneficial to deeply understand microbiological diversity of early childhood caries (ECC) at various stages and inform effective strategies for ECC prevention.