There is increasing evidence of an association between periodontitis/tooth loss and oral, gastrointestinal, and pancreatic cancers. Periodontal disease, characterized by chronic inflammation and microbial dysbiosis, is an important risk factor for orodigestive carcinogenesis. Porphyromonas gingivalishas been suggested as a key pathogen in chronic periodontitis that causes both dysbiosis and maladaptive immune response. This review focuses on P. gingivalis.It focuses on increasing recognition of the relationship between oral and digestive cancers. Porphyromonas gingivalis , abundant recovered from oral squamous cell carcinoma (OSCC). It has demonstrated a direct relationship between recently established models of tumorigenesis. P. gingivalis and carcinogenesis. It upregulates specific receptors on bacteria, OSCC cells and keratinocytes, induces epithelial-to-mesenchymal (EMT) transition of normal oral epithelial cells, and activates metalloproteinase-9 and interleukin-8 in cultures of carcinoma cells. In addition, P. gingivalis accelerates cell turnover and suppresses apoptosis in cultures of primary oral epithelial cells. In oral cancer cells, the cell cycle is stopped and has no effect on apoptosis, but macroautophagy is increased. Porphyromonas gingivalis It promotes distant metastasis and chemoresistance to anti-cancer agents and accelerates the proliferation of oral tumor cells by influencing gene expression of defensins, non-canonical activation of peptidyl-arginine deiminase and β-catenin. The pathogen also converts ethanol to the carcinogenic intermediate, acetaldehyde. In addition, P. gingivalis It can be associated with precancerous gastric and colon lesions, esophageal squamous cell carcinoma, carcinoma of the head and neck (larynx, throat, lips, mouth and salivary glands), and pancreatic cancer. Involvement of distant organs It clearly highlights that P. gingivalis is sick. It has systemic tumorigenic effects in addition to local effects in its natural region, the oral cavity. Although infection with other bacteria, viruses and fungi occurs in periodontitis, P. gingivalis associated with cancer, even without periodontitis. Therefore P. gingivalisThere may be a direct relationship between oral and digestive system cancers.