Periodontitis induced by heat-killed Pg did not further increase the total bacterial load (Additional file 1: Fig. S8) but led to increased gene expression levels of MCP-1, TNF-α, and IL-1β in the gums of AD mice (Fig. 4b) and CRP levels in the plasma (Additional file 1: Fig. S2b). The gene discussed is TNF; the disease is periodontitis.