Ethnicity-specific microbiome in early childhood caries: a functional perspective of oral biofilm

The disparity in tooth decay among young children has long been demonstrated in national surveillance data. While various factors including family, culture, access to health insurance, and medical infrastructure have been studied, the global transcriptomic perspective remains underexplored. Employing RNA-Seq technology, we examine functional and taxonomic differences in caries-associated microbial activity between two high-risk populations. Besides a core set of well-established cariogenic organisms, we observed significant and consistent differences in the active microbial communities between these two high-risk populations, African American (AA) and Latin American Hispanic (LAH) children. In AA children, Pseudopropionibacterium propionicum and Cardiobacterium hominis consistently showed the highest caries-related gene expression. In contrast, among LAH children, Propionibacterium acidifaciens, Selenomonas sp., Rothia dentocariosa, Atopobium parvulum, and Streptococcus sanguinis were the primary drivers of gene expression in caries lesions. By identifying the unique microbial mechanisms and pathways active in each population, we can better define the core factors required for caries development and uncover how differences in microbial function contribute to persistent disparities.