Periodontal treatment causes a longitudinal increase in nitrite‐producing bacteria

Abstract

AbstractBackgroundThe oral microbiome‐dependent nitrate (NO3−)–nitrite (NO2−)–nitric oxide (NO) pathway may help regulate blood pressure. NO2−‐producing bacteria in subgingival plaque are reduced in relative abundance in patients with untreated periodontitis compared with periodontally healthy patients. In periodontitis patients, the NO2−‐producing bacteria increase several months after periodontal treatment. The early effects of periodontal treatment on NO2−‐producing bacteria and the NO3−–NO2−–NO pathway remain unknown. The aim of this study was to determine how periodontal treatment affects the oral NO2−‐producing microbiome and salivary NO3− and NO2− levels over time.MethodsThe subgingival microbiota of 38 periodontitis patients was analysed before (baseline [BL]) and 1, 7 and 90 days after periodontal treatment. Changes in NO2−‐producing bacteria and periodontitis‐associated bacteria were determined by 16s rRNA Illumina sequencing. Saliva samples were collected at all‐time points to determine NO3− and NO2− levels using gas‐phase chemiluminescence.ResultsA significant increase was observed in the relative abundance of NO2−‐producing species between BL and all subsequent timepoints (all p < 0.001). Periodontitis‐associated species decreased at all timepoints, relative to BL (all p < 0.02). NO2−‐producing species negatively correlated with periodontitis‐associated species at all timepoints, with this relationship strongest 90 days post‐treatment (ρ = −0.792, p < 0.001). Despite these findings, no significant changes were found in salivary NO3− and NO2− over time (all p > 0.05).ConclusionsPeriodontal treatment induced an immediate increase in the relative abundance of health‐associated NO2−‐producing bacteria. This increase persisted throughout periodontal healing. Future studies should test the effect of periodontal treatment combined with NO3− intake on periodontal and cardiovascular health.