Characterizing the oral microbiota of adolescents: results from the Generation R Study

Objective The objective of this study was to describe the microbial signature of the oral cavity of adolescents from the general population. We also aimed assess the impact of technical covariates related to sample collection and analysis on the microbiota data. Methods Within the Generation R Study, supragingival biofilm samples were collected at age 13 for microbiota profiling. Microbial data were obtained using 16S rRNA gene sequencing (V3–V4 region) and analysed at three levels: core microbiota composition, alpha diversity (Shannon, Chao1 index; linear regression), and beta diversity (weighted UniFrac distance; PERMANOVA). Results Participants (n = 4,645; 13.6 ± 0.38 years) shared a large core microbiota consisting of 23 different genera, with the five most abundant and prevalent— Streptococcus , Rothia , Haemophilus , Veillonella , and Neisseria —being well-known early colonizers of the dental biofilm. Among the technical covariates, sampling time was identified as the most impactful and showed a negative association with diversity (early-morning vs late-afternoon: Shannon; β:-0.54, 95%CI:-0.61;-0.46). Conclusion This study revealed a high similarity in oral microbiota of adolescents from the general population at the genus level, while highlighting the need to register and adjust studies for potential technical covariates. The characterization of oral microbiota in this study population provides a unique opportunity for future studies exploring the link between adolescents' oral microbiota and both oral and systemic health.