Intra‐oral single‐site comparisons of periodontal and peri‐implant microbiota in health and disease

Abstract Objective Periodontitis and peri‐implantitis are oral infectious–inflammatory diseases that share similarities in their pathology and etiology. Our objective was to characterize the single‐site subgingival and submucosal microbiomes of implant‐rehabilitated, partially dentate Chinese subjects ( n = 18) presenting with both periodontitis and peri‐implantitis. Materials and methods Subgingival/submucosal plaque samples were collected from four clinically distinct sites in each subject: peri‐implantitis submucosa (DI), periodontal pocket (DT), clinically healthy (unaffected) peri‐implant submucosa (HI), and clinically healthy (unaffected) subgingival sulcus (HT). The bacterial microbiota present was analyzed using Illumina MiSeq sequencing. Results Twenty‐six phyla and 5,726 operational taxonomic units (OTUs, 97% sequence similarity cutoff) were identified. Firmicutes, Proteobacteria, Fusobacteria, Bacteroidetes, Actinobacteria, Synergistetes, TM7, and Spirochaetes comprised 99.6% of the total reads detected. Bacterial communities within the DI, DT, HI, and HT sites shared high levels of taxonomic similarity. Thirty‐one “core species” were present in >90% sites, with Streptococcus infantis/mitis/oralis (HMT‐070/HMT‐071/HMT‐638/HMT‐677) and Fusobacterium sp. HMT‐203/HMT‐698 being particularly prevalent and abundant. Beta‐diversity analyses (PERMANOVA test, weighted UniFrac) revealed the largest variance in the microbiota was at the subject level (46%), followed by periodontal health status (4%). Differing sets of OTUs were associated with periodontitis and peri‐implantitis sites, respectively. This included putative “periodontopathogens,” such as Prevotella , Porphyromonas , Tannerella , Bacteroidetes [G‐5], and Treponema spp. Interaction network analysis identified several putative patterns underlying dysbiosis in periodontitis/peri‐implantitis sites. Conclusions Species (OTU) composition of the periodontal and peri‐implant microbiota varied widely between subjects. The inter‐subject variations in subgingival/submucosal microbiome composition outweighed differences observed between implant vs. tooth sites, or between diseased vs. healthy (unaffected) peri‐implant/periodontal sites.