Genetic Contributions to Shaping the Subgingival Microbiome: A Twin Study

Objectives: Acquisition of bacteria into the subgingival microenvironment is influenced by both heritable and environmental factors. Our objective was to investigate the contributions of genetics to acquisition and maturation of the healthy microbiome using a twin model stratified by dentition stage.
Methods: 226 dizygotic and 166 monozygotic twins in predentate, primary, mixed, early permanent (12–20 years) and late permanent dentition stage (20–30 years) were enrolled. Subgingival plaque was collected from representative teeth, DNA isolated and the 16S gene sequenced on the Illumina platform targeting the V1-V3 and V6-V9 regions. Bacterial identification and abundance calculation were done by aligning the sequences against the Human Oral Microbiome Database (HOMD) using the QIIME pipeline.
Results: Monozygotic twin dyads did not demonstrate greater microbial similarity than dizygotic dyads in any dentition state. However, heritability analysis revealed that genetics may contribute to acquisition of 30 species, including F. nucleatum subsp. vincentii and S. gordonii.
Conclusions: While the contributions of genetics to community assembly in the oral microbiome are not evident using the twin model, certain species appear to be heritable.