Despite that some probiotics such as Dubosiella and Lachnospiraceae_UCG-006 [40,41] were observed as abundant in HGF-Tg mice with periodontitis, we found that the pro-inflammatory bacteria g_Streptococcus, g_unclassified_f_Ruminococcaceae, Prevotellaceae_UCG-001, and Desulfovibrio_fairfieldensis [42,43,44,45] were upregulated by HGF when periodontitis occurred. The gene discussed is HGF; the disease is periodontitis.