Analysis of Salivary Microbial Community in Deciduous Children with High Caries

Objectives: Caries is the most common oral bacterial infectious disease. It is speculated that saliva of deciduous dentition children with high incidence of caries has unique microbial community characteristics.
Methods: Fourteen high caries deciduous children and 27 caries-free deciduous children were selected according to WHO diagnostic criteria. Saliva and plaque mixture were taken from each child after brushing teeth, bacterial genomic DNA was extracted, V3-V4 fragment of 16S rRNA gene was amplified by PCR, and Illumina Miseq high-throughput sequencing was performed.Alpha diversity among different groups was compared by independent sample t test. The differences of Beta diversity among groups were compared by using R language Vegan package for multivariate variance analysis based on Unifrac distance matrix.
Results: There was no significant difference in relative abundance of species in saliva between high caries deciduous dentition children and non-caries deciduous dentition children. Statistical analysis based on Unifrac distance matrix showed that there was no significant difference in salivary microbial community structure between high caries and non-caries children. There were significant differences in relative abundance of species between the two groups: Streptococcus, Veironcoccus and ciliates. Genus and Lactobacillus.
Conclusions: The salivary species abundance of children with high caries and caries-free deciduous dentition was similar. There was no significant difference in the microbial community structure, but the relative species abundance was different.