Taxonomic composition of the oral microbiome and its relationship with immune parameters in periodontal inflammatory disease

Abstract

Elucidating the role of periodontopathogenic microorganisms in inflammatory periodontal diseases and the immune response they trigger in the pathogenesis may open up new opportunities for the diagnosis, prevention, and treatment of this pathology. The aim is to analyze the relationships between the taxonomic features of the microbiome of the gingival sulcus/periodontal pocket contents and immunological indicators in patients with gingivitis and chronic generalized periodontitis (CGP) of varying severity. Materials and methods. The 16S rRNA gene was sequenced according to the Illumina protocol to determine the species composition of the microbiome in the gingival sulcus and periodontal pocket of 84 patients. The concentration of pro- and anti-inflammatory cytokines was determined in the selected samples using enzyme-linked immunosorbent assay. The peripheral blood of the patients was evaluated for the content of immunoglobulins A, M, and G and the phagocytic activity of neutrophils. Statistical data processing and correlation analysis were performed using the Statistica 10 software package. Results and discussion. It was found that patients with inflammatory periodontal diseases had increased levels of IL-2, TNFα, and IL-4 in their oral fluid, as well as sIgA, while there was a statistically significant decrease in the levels of IL-6 and IL-10. In the peripheral blood of patients with CGP, there was a decrease in the phagocytic activity of leukocytes and dysgammaglobulinemia. A significant “positive” correlation was found between the presence of representatives of the V. dispar species in the oral microbiome and increased levels of TNFα, IL-2, IL-4, and sIgA (τ = 0.27...0.36, p < 0.05), as well as a negative correlation between the occurrence of F. nucleatum, T. forsythia, and F. alocis with a number of immunological parameters — TNFα, IL-2, IL-4, sIgA, IgA, IgM, IgG (τ = – 0.57... – 0.86, p < 0.01). Conclusion. The presence of P. gingivalis, F. nucleatum, F. alocis, and V. dispar in the oral microbiome of patients with chronic generalized periodontitis contributes to the suppression of cellular and humoral immunity and is a potential biomarker of severe and progressive disease, which should be taken into account during comprehensive therapy.