Bacteria of genus Filifactor in patients with periodontitis and type 2 diabetes in accordance with metagenomic analysis of the periodontal microbiome

Introduction. Periodontal diseases are a common pathology with chronic periodontitis (CP) being the most severe form. This polymicrobial disease has become a problem of great importance in recent years due to the possibility of development of systemic effects associated with this condition. CP is often combined with type 2 diabetes (T2D). The main cause of the occurrence and development of periodontal pathology is played by the bacteria Filifactor alocis, the least studied and most recently discovered periodontal pathogen. The objective of this study was to identify bacteria of genus Filifactor as part of the periodontal microbiome associated with CP and T2D and to clarify the mechanisms of their possible influence on associated metabolic processes according to comparative metagenomic analysis. Materials and methods. A metagenomic study of the microbiome of periodontal pocket samples from 28 patients with CP associated with T2D and 22 patients with CP, as well as the microbiome of dental gingival sulcus samples from 19 clinically healthy individuals was performed. 16S-sequencing of the ribosomal RNA gene was used to determine the taxonomic composition of the microbiome. Prediction of metabolic pathways involving the microbiome was performed with the help of the shotgun method. Results. Filifactor bacteria were the one of the most frequent microorganisms only in patients with CP associated with T2D. The rate of identification of these bacteria was correlated with low predicted metagenomic levels of fatty acid biosynthesis and pyrimidine metabolism in the affected area. Conclusion. The detection frequency of Filifactor bacteria in patients associated with CP and T2D is negatively correlated with the selected features of putative metabolic pathways of the microbiome, which include fatty acid biosynthesis and pyrimidine metabolism.