Nitrate-Reducing Commensals Reshape Oral Biofilm Ecology and Reveal Hcp as a Critical Determinant of Porphyromonas gingivalis Persistence

Dietary nitrate supplementation is being explored as a way to suppress oral pathogens through the generation of reactive nitrogen species (RNS) like nitrite and nitric oxide by nitrate-reducing bacteria. However, how periodontal pathogens resist this nitrosative stress in complex polymicrobial communities has been unclear. The authors previously identified the hybrid cluster protein (Hcp) as a major nitrosative stress defense factor in Porphyromonas gingivalis, showing ~170-fold induction of hcp expression after nitrite exposure and its requirement for survival at physiologically relevant nitrite concentrations.