P1350 The Role of oral Porphyromonas gingivalis and Its Outer Membrane Vesicles in Inflammatory Bowel Disease

Abstract Background The etiology of Inflammatory bowel disease (IBD) remains elusive, but emerging evidence suggests a potential link between oral microbiota and IBD. Porphyromonas gingivalis(Pg.), a major pathogen in periodontal disease, and its outer membrane vesicles(OMVs) may play significant roles in the development and progression of IBD. Methods Animal models of IBD were established to observe the impact of Pg. and its OMVs on intestinal inflammation. In vitro cell culture was conducted to explore the interaction between Pg.-OMVs and intestinal epithelial cells and immune cells. Results Through the analysis of salivary microbiota in IBD patients and healthy individuals, we observed a significant increase in the abundance of Pg. in the saliva of IBD patients. OMVs may serve as a novel medium for oral bacteria to communicate with the gut. Our findings indicate that Pg.-OMVs can promote the development of IBD through various mechanisms. Firstly, they can disrupt intestinal barrier function by promoting inflammation in intestinal epithelial cells and degrading tight junction proteins. Additionally, Pg.-OMVs carry pathogenic factors and pro-inflammatory molecules, which activate intestinal macrophages to polarize towards the M1 phenotype, inducing inflammatory responses. Beyond systemic effects, we discovered that the key virulence factor LPS of Pg. can stimulate oral epithelial cells to secrete exosomes. These exosomes exhibit pro-inflammatory properties, including the disruption of the intestinal mucosal barrier and the promotion of macrophage polarization towards the M1 phenotype, with subsequent secretion of inflammatory factors. Conclusion Porphyromonas gingivalis and its outer membrane vesicles play important roles in the pathogenesis of IBD. Understanding these mechanisms provides new insights into the relationship between oral health and IBD and may lead to the development of novel diagnostic and therapeutic strategies for IBD.