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 analysed using Illumina MiSeq sequencing. Results: 26 phyla and 5,726 Operational Taxonomic Units (OTUs, 97% sequence similarity cut-off) 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. 31 ‘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 versus tooth sites, or between diseased versus healthy (unaffected) peri-implant/periodontal sites.