Oral Microbiome Profile of Gingivitis and Periodontitis by Next-Generation Sequencing

Abstract Background: Periodontal diseases,including gingivitis and periodontitis, are crucial public health concerns owing to their high prevalence in all age groups. The oral microbiome plays an important role in the development and progression of periodontal disease. Aim: The purpose of this study was to perform a representative analysis of the salivary oral microbiome using next-generation sequencing associated with gingivitis and periodontitis and to identify novel candidate microbial biomarkers for the diagnosis and prediction of periodontal diseases. Methods: In total, 102 participants (52 women, mean age: 46.49 ± 16.03 years) were included in this cross-sectional study, consisting of 33 healthy controls, 41 patients with gingivitis, and 28 patients with periodontitis. The salivary oral microbiomes of the 102 participants were investigated using 16S rRNA metagenomic sequencing, and the microbial profiles of each group were compared to identify new biomarkers specific to each group. Results: The oral microbiota belonging to 12 phyla, 182 genera, and 409 species were identified in 102 saliva samples. Firmicutesand Actinobacteria were the most dominant phyla, which constituted 87.7% of the total sequences in all three groups. The abundance of amplicon sequence variants was significantly higher in the gingivitis (184.56 ± 67.43)and periodontitis groups (193.29 ± 81.95) compared to healthy controls (146.91 ± 44.4) (p = 0.046). Chao1 diversity was significantly higher in the gingivitis and periodontitis groups compared to the control group (p = 0.046). Based on the linear discriminative analysis (LDA) scores (>2), Tenericutes, Mollicutes, Mycoplasmatales, Mycoplasmataceae, Mycoplasma, Bacteroidaceae, and Phocaeicola were significantly enriched in the gingivitis group. Based on the LDA scores (>2), Synergistetes, Synergistia, Synergistales, Synergistaceae, Fretibacterium, Sinanaerobacter, and Filifactor were identified as oral microbiota related to periodontitis. The relative abundances of Fretibacterium fastidiosum, Sinanaerobacter chloroacetimidivorans, and Filifactor alocis were the highest in the periodontitis group and the lowest in the control group (all p < 0.01). Regarding the red complex, the relative abundance of Porphyromonas gingivalis was significantly higher in the periodontitis group than that in the healthy control and gingivitis groups (p = 0.014). The relative abundances of Treponema denticola and Tannerella forsythia were not significantly different between the periodontitis group and the other groups(p > 0.05). Conclusion: No single species has been identified as the primary causative agent of periodontitis. However, a more reasonable explanation is multibacterial periodontitis. The salivary oral microbiome, which differentiates patients with gingivitis and periodontitis from healthy controls, has unique characteristics. In addition to P. gingivalis, F. fastidiosum, S. chloroacetimidivorans, and F. alocis as well as their combinations have potential as new biomarkers for periodontitis.