PMID: J Oral Sci. 2017 Oct 6. Epub 2017 Oct 6. PMID: 28993578 Abstract Title: Characterizations of oral microbiota in nursing home residents. Abstract: Over 700 species are discovered in the oral cavity. Several studies have suggested that periodontitis is associated with systemic disorders like diabetes mellitus, indicating a role. The relationship between oral microbiota and diabetes has not been clarified. Therefore, we conducted microbiome evaluation of saliva samples obtained from 15 older citizens (3 with type 2 diabetes mellitus [DM] and 12 with diabetes [non-DM]) at three different nursing homes, along with 9 young wholesome controls (HC). Genomic DNA was extracted from each sample, and then the V4 region of the 16S rRNA gene was amplified and sequenced. Alpha diversity, in terms of taxonomic unit richness, was significantly greater in samples in the non-DM group than. UniFrac distance evaluation revealed that salivary microbial communities at the DM group were clustered. What’s more, from the DM group, Actinomyces and Selenomonas revealed significantly higher abundance, whereas Alloprevotella showed abundance. Though our findings were restricted by the small sample size, oral bacterial diversity at the DM group was clearly distinct from that at the non-DM group.