[Oral-gut axis: the microbial and immune bridge linking periodontitis to inflammatory bowel disease]

Periodontitis and inflammatory bowel disease (IBD) are common chronic inflammatory diseases affecting the oral cavity and gut, respectively. Recent researches suggest a potential bidirectional link between them via the oral-gut axis. On one hand, periodontal pathogens, notably Porphyromonas gingivalis, can ectopically colonize the gut, driving and exacerbating intestinal inflammation through mechanisms such as disrupting the gut barrier and inducing helper T cell 17/regulatory T cell imbalance. On the other hand, the systemic inflammatory environment, immune-metabolic disturbances, and oral-specific lesions caused by IBD can significantly increase the risk and severity of periodontal tissue destruction. This review summarizes the current understanding of the microbial and immune mechanisms underlying the interrelationship between periodontitis and IBD. It aims to encourage further validation of causality through longitudinal cohort studies, exploration of microbiome-targeted interventions, and multidisciplinary collaboration, ultimately facilitating the development of integrated prevention and treatment strategies based on the oral-gut axis.