, but not other bacterial taxa, are associated with childhood caries regardless of age in a South China population.

Background: Human microbiome dysbiosis is related to various human diseases, and identifying robust and consistent biomarkers that apply in different populations is a key challenge. This challenge arises when identifying key microbial markers of childhood caries.

Methods: We analyzed unstimulated saliva and supragingival plaque samples from children of different ages and sexes, performed 16S rRNA gene sequencing, and sought to identify whether consistent markers exist among subpopulations by using a multivariate linear regression model.

Results: We found that and bacterial taxa were associated with caries in plaque and saliva, respectively, while and were found in plaque isolated from children of different ages in preschool and school. These identified bacterial markers largely differ between different populations, leaving only as a significant caries-associated phylum in children. is a newly identified phylum, and our taxonomic assignment database could not be used to identify its specific genus.

Conclusion: Our data indicated that, in a South China population, oral microbial signatures for dental caries show age and sex differences, but might be a consistent signal and worth further investigation, considering the lack of research on this microbe.