Microbial signatures of health, gingivitis, and periodontitis

Abstract

The subgingival crevice harbors diverse microbial communities. Shifts in the composition of these communities occur with the development of gingivitis and periodontitis, which are considered as successive stages of periodontal health deterioration. It is not clear, however, to what extent health‐ and gingivitis‐associated microbiota are protective, or whether these communities facilitate the successive growth of periodontitis‐associated taxa. To further our understanding of the dynamics of the microbial stimuli that trigger disruptions in periodontal homeostasis, we reviewed the available literature with the aim of defining specific microbial signatures associated with different stages of periodontal dysbiosis. Although several studies have evaluated the subgingival communities present in different periodontal conditions, we found limited evidence for the direct comparison of communities in health, gingivitis, and periodontitis. Therefore, we aimed to better define subgingival microbiome shifts by merging and reanalyzing, using unified bioinformatic processing strategies, publicly available 16S ribosomal RNA gene amplicon datasets of periodontal health, gingivitis, and periodontitis. Despite inherent methodological differences across studies, distinct community structures were found for health, gingivitis, and periodontitis, demonstrating the specific associations between gingival tissue status and the subgingival microbiome. Consistent with the concept that periodontal dysbiosis is the result of a process of microbial succession without replacement, more species were detected in disease than in health. However, gingivitis‐associated communities were more diverse than those from subjects with periodontitis, suggesting that certain species ultimately become dominant as dysbiosis progresses. We identified the bacterial species associated with each periodontal condition and prevalent species that do not change in abundance from one state to another (core species), and we also outlined species co‐occurrence patterns via network analysis. Most periodontitis‐associated species were rarely detected in health but were frequently detected, albeit in low abundance, in gingivitis, which suggests that gingivitis and periodontitis are a continuum. Overall, we provide a framework of subgingival microbiome shifts, which can be used to generate hypotheses with respect to community assembly processes and the emergence of periodontal dysbiosis.

Molecular Screening and Analysis Reveal Novel Oral Site-Specific Locations for the Cariogenic Pathogen Scardovia wiggsiae

“…In addition to these novel insights, this study also provides the first evidence of SW presence from the gingival crevice, an area more traditionally associated with periodontal pathogens and anaerobic Gram-negative microbes [ 42 , 43 ]. Although the majority of GCF-associated SW-positive samples were found among patients with multi-site SW-positive results, at least one single-site positive sample was found to harbor SW only in the GCF—which may suggest that more detailed and specific studies are needed to better understand the potential microbial interactions in the subgingival biofilm and the gingival crevice [ 44 , 45 , 46 ].…”

Microbiome and Cancers of the Esophagus: A Review

“…Periodontal disease involves the interplay between oral microbiome and the host immune response. Gingivitis entails mild and reversible inflammation of the gums, whereas periodontitis involves tissue destruction and loss of tooth support [ 94 , 128 ]. In periodontitis, a profound shift in the composition of subgingival communities occurs, with an enrichment of Gram-negative anaerobic bacteria, and these changes in the subgingival microbiome associated with periodontitis development are markedly different from those in gingivitis [ 128 ].…”

“…Gingivitis entails mild and reversible inflammation of the gums, whereas periodontitis involves tissue destruction and loss of tooth support [ 94 , 128 ]. In periodontitis, a profound shift in the composition of subgingival communities occurs, with an enrichment of Gram-negative anaerobic bacteria, and these changes in the subgingival microbiome associated with periodontitis development are markedly different from those in gingivitis [ 128 ]. Among those enriched are the triad of Porphyromonas gingivalis , Treponema denticola , and Tannerella forsythia (known as the “red complex”), which were classically considered as the predominant pathogens in periodontitis [ 94 , 125 , 129 ].…”

“…Among those enriched are the triad of Porphyromonas gingivalis , Treponema denticola , and Tannerella forsythia (known as the “red complex”), which were classically considered as the predominant pathogens in periodontitis [ 94 , 125 , 129 ]. Culture-independent analyses have expanded this list of periodontitis-associated taxa enriched in disease to include Porphyromonas endodontalis , several Treponema spp., Prevotella intermedia , Filifactor alocis , Fretibacterium spp., and Selenomonas spp., among others [ 125 , 128 , 129 ]. In addition, Actinomyces spp., Rothia spp., and Streptococcus sanguinis are the main health-associated taxa that are often depleted in periodontitis, and Campylobacter gracilis and Fusobacterium nucleatum ss.…”

“…Inflammation may be a key driver of the overgrowth of periodontitis microorganisms through tissue destruction providing a rich source of nutrients, and these bacteria can further promote inflammation to maintain their selective dominance [ 94 , 130 ]. Many of the periodontitis-related pathogens are also present in health, rather than being exogenous pathogens absent in health—it appears that some species become more dominant in a disease state, although they are also present at low levels in health [ 94 , 128 ]. For example, P. gingivalis is a minor member of the oral microbial community, but it is consistently associated with the initiation and progression of periodontal disease.…”