ABSTRACT
BACKGROUND: Dental implants replace missing teeth in at least 100 million people, yet over one million implants fail every year due to peri-implantitis, a bacterially induced inflammatory disease. Our ability to treat peri-implantitis is hampered by a paucity of information on host-microbiome interactions that underlie the disease. Here, we present the first open-ended characterization of transcriptional events at the mucosal-microbial interface in the peri-implant crevice. METHODS: We simultaneously sequenced microbial and human mRNA from five pairs of healthy and diseased implants from the same patient and used graph theoretics to examine correlations between microbial and host gene expression in the peri-implant crevice. RESULTS: We identified a transcriptionally active peri-implant microbiome surrounding healthy implants. Microbial genes encoding phenylalanine, tyrosine, and tryptophan biosynthesis, cysteine, methionine, arginine, proline, and histidine metabolism correlated to human genes encoding cell development, metabolism, morphogenesis, adhesion, gap junctions, cell-cell signaling, and immunoinflammatory pathways, suggesting a role for commensals in protecting epithelial integrity. In disease, we found 4- to 200-fold upregulation in microbial genes encoding biofilm thickness, heme transport and utilization, and Gram-negative cell membrane synthesis. These genes correlated with mucosal zinc finger proteins, apoptosis, membrane transport, inflammation, and cell-cell communication. CONCLUSIONS: Within the limitations of a small sample size, our data suggest that microbial dysbiosis in the peri-implant sulcus might promote abandonment of host-bacterial transactions that dictate health and instead drive a move towards chronic programming of a non-healing wound.
