Diversity of the oral microbiome between dentate and edentulous individuals

BACKGROUND: Measurement of saliva microbes is promoted as a way to detect oral and systemic disease, yet there is a multitude of factors that affect the oral microbiome. The salivary microbiome is influenced by oral biofilm of shedding (epithelial) and non-shedding (tooth) surfaces. METHODS: To gauge the ability of salivary microbial analytics to distinguish between edentulous and dentate oral conditions, we looked for differences in the saliva microbiome of subjects with and without teeth. Fifty-two dentate and 49 edentulous subjects provided stimulated saliva samples. 16S rRNA gene sequencing, QIIME-based data processing, and statistical analysis were done using several different analytical approaches to detect differences in the salivary microbiome between the two groups. RESULTS: Bacteria diversity was lower in the edentulous group. Remarkably, all 31 of the most significant differences in taxa were deficits that occur in the edentulous group. As one might expect many of these taxa are attributed to dental plaque and gingival sulcus associated bacteria. CONCLUSION: In sum, the measurement of 16S rRNA genes in the bacteria of the saliva can be used to reproducibly measure differences in the oral microbiome that occur with edentulism, mainly the lack of tooth and tooth-related structures.