High-throughput sequencing identifies salivary microbiota in Chinese caries-free preschool children with primary dentition.

OBJECTIVES

The study aimed at identifying salivary microbiota in caries-free Chinese preschool children using high-throughput sequencing.

METHODS

Saliva samples were obtained from 35 caries-free preschool children (18 boys and 17 girls) with primary dentition, and 16S ribosomal DNA (rDNA) V3-V4 hypervariable regions of the microorganisms were analyzed using Illumina MiSeq.

RESULTS

At 97% similarity level, all of these reads were clustered into 334 operational taxonomic units (OTUs). Among these, five phyla (Firmicutes, Proteobacteria, Actinobacteria, Bacteroidetes, and Candidate division TM7) and 13 genera (, , , , , , , , , , , , and ) were the most dominant, constituting 99.4% and 89.9% of the salivary microbiota, respectively. The core salivary microbiome comprised nine genera (, , , , , , , ,and ). Analysis of microbial diversity and community structure revealed a similar pattern between male and female subjects. The difference in microbial community composition between them was mainly attributed to (=0.023). Furthermore, functional prediction revealed that the most abundant genes were related to amino acid transport and metabolism.

CONCLUSIONS

Our results revealed the diversity and composition of salivary microbiota in caries-free preschool children, with little difference between male and female subjects. Identity of the core microbiome, coupled with prediction of gene function, deepens our understanding of oral microbiota in caries-free populations and provides basic information for associating salivary microecology and oral health.