Strain-level genomic variation of <i>Streptococcus mutans</i> and early childhood caries in preschool children from Northern Arizona and Hawaii

The observed correlation between <i>S. mutans</i> genotype and ECC risk, together with the finding that higher-risk genotypes were more prevalent among at least one disproportionately affected group, suggests that strain-level variation may contribute to population-level disparities. The identification of functional markers linked to ECC risk further supports biologically meaningful strain-specific effects and warrants further investigation. These findings highlight the value of incorporating microbial genetic diversity into ECC risk frameworks, while recognizing that fully disentangling microbial contributions will require studies that integrate social, behavioral, and dietary determinants.