Bacterial translocation signatures and subgingival microbiome in individuals with periodontitis

Objectives: To determine bacterial blood translocation signatures and their association with the subgingival microbiota in individuals with and without periodontitis. Materials and methods: Cross-sectional study. DNA was extracted from blood and subgingival samples of individuals with periodontitis (n = 21) and control volunteers (n = 24). Subgingival microbiota was explored by 16 S rRNA gene sequencing. Detection frequency and loads of total bacteria, Porphyromonas gingivalis (Pg), Porphyromonas endodontalis (Pe) and Fusobacterium nucleatum (Fn) were determined in all samples using quantitative polymerase chain reaction (qPCR). The statistical analysis was performed using STATA 16. Results: Subgingival samples from individuals with periodontitis presented higher relative abundance of Prevotella intermedia, F. nucleatum subsp. vincentii, Treponema sp. HMT 237, Alloprevotella tannerae, Filifactor alocis, Pg, Treponema denticola and Pe, and higher loads of total bacteria, Pg, Pe and Fn, compared to the control group (p < 0.001). While Pg and Fn were not detected in blood, Pe was detected in 95% of individuals with periodontitis and 83% of the control ones (p = 0.205), with higher loads in blood samples from periodontitis (p = 0.034). No significant correlation was found between subgingival bacterial loads and blood loads of Pe in periodontitis and control groups (p > 0.05). Conclusions: Individuals with periodontitis presented higher relative abundance and loads of periodontal bacteria in subgingival samples and higher Pe loads in blood samples, although further research is needed to understand the correlation between subgingival and blood bacterial loads. Clinical relevance: The present study showed higher loads of Pe in the blood of individuals with periodontitis, suggesting potential extraoral dissemination and a linking mechanism with several systemic diseases.