Characterizations of oral microbiota in elderly nursing home residents with diabetes

Abstract

Over 700 bacterial species have been detected in the oral cavity. Several studies have suggested that periodontitis is associated with systemic disorders such as diabetes mellitus, indicating a key role for oral microbiota in human health. However, the relationship between oral microbiota and diabetes has not been well clarified. Therefore, we conducted microbiome analysis of saliva samples obtained from 15 elderly residents (3 with type 2 diabetes mellitus [DM] and 12 without diabetes [non-DM]) at three different nursing homes, as well as 9 young healthy 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 operational taxonomic unit richness, was significantly higher in samples from the non-DM group than in those from the HC group. Weighted UniFrac distance analysis showed that salivary microbial communities in the DM group were separately clustered. Furthermore, in the DM group, Actinomyces and Selenomonas showed significantly higher abundance, whereas Alloprevotella showed significantly lower abundance, relative to the non-DM group. Although our findings were limited by the small sample size, oral bacterial diversity in the DM group was clearly different from that in the non-DM group.

Oral Microbiome Signatures in Diabetes Mellitus and Periodontal Disease

“…Emerging data derived from high-throughput metagenomic sequencing of the oral microbiome with 16S rDNA or rRNA support the role of these microorganisms in the development of DM, but the findings remain controversial (Long et al 2017;Ogawa et al 2017;Tam et al 2018;Saeb et al 2019). Similar to our findings, these studies showed differences between glycemic statuses and the proportions of several phyla.…”

The salivary microbiome of diabetic and non‐diabetic adults with periodontal disease

“…A study of supragingival plaque, as well as tongue scrapings and saliva samples used metagenomics and 16S rRNA sequencing for a more comprehensive characterization of the oral microbiome . However, due to ease of sampling, salivary samples provide a distinctive advantage for screening purposes and have been used in various studies of health and disease . In addition to sampling, the choice of hypervariable regions of the 16S rRNA gene that have been sequenced have an impact on characterizing the diversity of the oral microbiome .…”

“…42 However, due to ease of sampling, salivary samples provide a distinctive advantage for screening purposes and have been used in various studies of health and disease. 10,16,[43][44][45][46][47] In addition to sampling, the choice of hypervariable regions of the 16S rRNA gene that have been sequenced have an impact on characterizing the diversity of the oral microbiome. 31 Another potential limitation is lack of sample replicates within our study design and thus we are not able to assess individual variability.…”

The salivary microbiota in health and disease

“…Several studies have compared SM in patients with diabetes to that of healthy controls by means of NGS, and in general, data show that diabetes associates with a decrease in bacterial diversity of SM [66][67][68]. In addition, higher salivary levels of P. gingivalis, T. forsythia and F. alocis were reported in patients with gestational diabetes [69], whereas only minor differences were identified in children with T2DM, when compared to obese and healthy controls, respectively [70].…”