Structure and Function of the Dental Plaque Microbiome in Eubiosis: A Systematic Review of Ethnic-Racial Influences

While a conserved core microbiome is shared across healthy individuals, significant interindividual taxonomic variation exists; however, the specific influence of genetic ancestry on supragingival plaque structure in eubiosis remains unclear. This systematic review analyzed evidence regarding taxonomic variations in supragingival plaque associated with ethnicity in systemically healthy populations. A search was conducted in PubMed, Scopus, ScienceDirect, and Scielo following PRISMA 2020 guidelines, covering literature up to October 2025. Cross-sectional studies using genomic sequencing or metagenomics were included, with quality assessed via the GRADE system. Six studies met eligibility criteria. Results identified a universal core microbiome structurally dominated by <i>Corynebacterium</i> spp. and <i>Streptococcus</i> spp. However, distinct ethnic-specific taxonomic signatures emerged, such as the enrichment of <i>Fusobacterium</i> spp. in African Americans and <i>Corynebacterium</i> spp. in Caucasians, alongside the exclusive presence of <i>Sneathia</i> spp. in Burmese individuals. Although a basal microbial architecture necessary for homeostasis exists, ethnicity acts as a biological filter defining distinctive bacterial profiles and differential susceptibilities. These findings suggest that while the core microbiome is conserved, the composition of peripheral species in the dental plaque hedgehog structure varies according to ancestry. This supports a transition from standardized dental care to personalized medicine oriented towards the patient's biological heritage.