Difference in oral microbial composition between chronic periodontitis patients with and without diabetic nephropathy

Background To investigate the difference in the structural composition of salivary flora between chronic periodontitis patients with and without diabetic nephropathy (DN). Methods Thirty salivary samples of 15 chronic periodontitis patients with DN (DN group) and 15 chronic periodontitis patients with diabetes but without DN (DM group) were subjected to pyrosequencing of polymerase chain reaction-amplified 16 s ribosomal RNA genes. After diversity testing, the differential flora were analyzed. The sequencing results were compared with GenBank database to determine the type of differential flora using species composition analysis, hierarchical cluster analysis, principal co-ordinate analysis, and species difference analysis. Results There were significant between-group differences with respect to Gemella , Selenomonas spp , Lactobacillales_unclassified, Bacteria-unclassified and Abiotrophia ( p < 0.05). Compared with DM group, the relative abundance of Selenomonas spp. in DN group was significantly higher; the area under the receiver operating characteristic curve of Selenomonas spp. was 0.713 ( P < 0.05). Multi-level biological identification and feature maps indicated that Selenomonas spp. might be used as a potential biomarker for DN patients. On binary logistic regression analysis, increase of Selenomonas spp. was related with DN. Conclusions We found significant between-group differences in the structural composition of oral flora. The increase in the relative abundance of Selenomonas spp. may be associated with DN in patients with chronic periodontitis.