Objective To explore the effects of periodontal inflammation on the functions of gut barrier (ecological barrier, mechanical barrier, and immune barrier) in mice.Methods Twenty male C57BL/6J mice were randomly divided into periodontitis (P) or control (C) groups. The P group was subjected under a 10-day ligation with Porphyromonas gingivalis to induce periodontitis, whereas the C group was ligated with sham. Maxillae were obtained to assess alveolar bone loss. The phylogenetic structure and diversity of microbial communities in the gut were analyzed by 16s rRNA pyrosequencing. Immunohistochemical analysis was performed to determine the expressions of occludin, claudin2, and NOD2 in the ileum.Results Compared with the C group, the P group displayed significant alveolar bone loss (P0.05). However, the ileum of the P group showed significantly upregulated occludin, claudin2, and NOD2 (P=0.039, P=0.011, and P=0.039, respectively).Conclusion Periodontal inflammation influences to some extent the mechanical and immune barrier functions of the mice gut.