In fact, our research group recently showed that ligature-induced periodontitis in rats was related to a significant decrease in gingival levels of IL-10, an anti-inflammatory cytokine [24] In the preset study, P. floribundum (10mg/kg) decreased TNF-α, IL1-β, and IL-8/CINC-1 gingival levels and transcription of TNF-α, IL1-β, RANK and RANKL genes, while elevated IL-10 gingival levels, which suggestes that the protective effect of P. floribundum may be related to the modulation of both pro- and anti-inflammatory cytokines levels in gingival tissue. The gene discussed is TNF; the disease is periodontitis.