The influence of saliva microbiota on dental caries progression in Korean children

Changes in salivary microbiota composition reportedly correlate with the development of dental caries in children; however, the mechanisms mediating this association remain unclear. Thus, the present study explored salivary microbiota patterns in children aged 6-12 years and their association with the incidence of dental caries. During a 4-year follow-up period, 12 children developed two or more caries and were subsequently matched to controls from a caries-free cohort (n = 338) based on age, sex, and lifestyle. To examine salivary microbiota, DNA was extracted from saliva samples and analyzed by 16S rRNA pyrosequencing. Interestingly, tThe salivary microbiota was more diverse in caries-free (CF) subject than those who developed dental caries (DC). Although Bboth groups exhibited similar shifts in microbiota composition along time, the association with caries was found in the analysis of function prediction. that did not appear to associate with the presence of caries. Moreover, The analysis of potential microbiome functions revealed that Granulicatella, Streptococcus, and Staphylococcus in the DC group mediated the bacterial invasion of epithelial cells, phosphotransferase system, and D-alanine metabolism, whereas Neisseria, Lautropia, and Leptrotrichia in CF subjects associated with bacterial motility protein, linoleic acid metabolism, and flavonoid biosynthesis. This suggests that functional metabolic differences in the salivary microbiota may be associated with the formation of caries. Collectively, these results further our understanding on the functional significance of the salivary microbiome in caries development, and may facilitate the identification of novel biomarkers and treatment targets.