Porphyromonas gingivalis is a key periodontal pathogen in the relationship between periodontal and gastroenterological diseases

Periodontal diseases are among the most common human ailments. At the beginning of the 21st century, the concept of “periodontal medicine” emerged, examining the relationship between periodontal pathology and other diseases. Currently, over 50 different somatic diseases are associated with periodontal pathology. Among various periodontal microorganisms, Porphyromonas gingivalis is considered a key periodontopathogen, potentially correlating with systemic diseases. We searched the PubMed database for sources published before November 1, 2025, that examined the relationship between Porphyromonas gingivalis and the development of systemic diseases. Due to the large number of sources found (1,042), we narrowed the search to consider the relationship between Porphyromonas gingivalis and the development of gastrointestinal diseases (193 sources). This review examines the relationship between Porphyromonas gingivalis and inflammatory bowel diseases (48 references) and non-alcoholic fatty liver disease (44 references). The data presented in the review demonstrate that Porphyromonas gingivalis is involved in the development and progression of inflammatory bowel diseases through alterations in the intestinal microbiota along the mouth-gut axis, disruption of the intestinal barrier and permeability, release of inflammatory mediators, and impaired immune response. In non-alcoholic fatty liver disease, Porphyromonas gingivalis is detected in liver tissue. Furthermore, a connecting mouth-gut-liver axis is formed, and bacterial translocation of Porphyromonas gingivalis into the systemic circulation becomes important, accompanied by the circulation of inflammatory mediators and immune complexes, and disruption of metabolic, inflammatory, and immunological homeostasis. Oral health promotion should be considered as an integral part of a healthy lifestyle in order to reduce the burden of chronic non-communicable and communicable diseases