P0213 Salivary Veillonella parvula from Crohn’s Disease Patients Exacerbates Intestinal Inflammation

Abstract Background The gut microbiota plays a significant role in the development of inflammatory bowel disease (IBD). There is a close interaction between the oral and gut microbiota. However, the role of the "oral-gut" microbial axis in the development of IBD is not yet clear. Methods 1. Analyzed oral-gut microbiota patterns in 97 IBD patients using 16S rDNA sequencing and bioinformatics methods. 2. A mouse colitis model with DSS was used. It was gavaged with oral microbiota from CD patients to assess the impacts on colitis and gut microbiota. 3. Isolated specific differential bacteria, Veillonella, from CD patient saliva and evaluated their effects on DSS-induced colitis in mice. Results 1. IBD patients had a reduced core gut microbiota, lower diversity (P < 0.05), and increased abundance of potential pathogens such as Escherichia-Shigella. 2. CD patients showed more correlations between saliva and fecal microbiota, with the most significant correlation between Veillonella in saliva and Escherichia-Shigella in fecal (P=0.00018) . 3. The mice which were gavaged with saliva from CD patients showed significant weight loss (P < 0.0001), reduced colon length (P=0.03), increased histopathological scores (P=0.01), decreased expression of colonic mucosal barrier proteins ZO-1 and E-cadherin, and exacerbated gut microbiota dysbiosis . 4. The mice which were gavaged with Veillonella parvula from CD patients showed significant weight loss (P < 0.0001), reduced colon length (P=0.02), increased histopathological scores (P=0.02), decreased expression of colonic mucosal barrier proteins ZO-1 and E-cadherin, and exacerbated gut microbiota dysbiosis. Conclusion The interplay between the oral and gut microbiota potentially influences the progression of IBD, with oral bacteria such as Veillonella possibly intensifying intestinal inflammation in IBD patients by disrupting the gut microbiota balance. Targeted modulation of the gut microbiota and interference with oral-gut microbial interactions may offer a promising therapeutic strategy for managing IBD.