P094 Impacts of 5-aminosalicylic acid on the intestinal microbiota leading to the anti-inflammatory effect

Abstract Background 5-aminosalicylic acid (5-ASA) is widely used for the treatment of inflammatory bowel disease (IBD), while its anti-inflammatory mechanisms remain controversial. The intestinal microbiota plays a certain role in pathogenesis IBD. We hypothesised that 5-ASA exerts effects by altering gut microbiota. Elucidating on and contribution to can lead development effective economical IBD medications. Methods Specific-pathogen-free (SPF) mice were orally administered 4 weeks. fecal bacterial compositions examined with 16S rRNA gene amplicon sequencing analysis 5-ASA-treatment group (5-ASA group) no-treatment (NT group). immune profiles colonic mucosa assessed. feces from female both groups gavaged into germ-free (GF) separated isolators. In each isolator, these dams NT dams) mated GF male mice. populations CD4+ T cells mesenteric lymph nodes (MLN) mucosal analysed their pups. pups dextran sulfate sodium (DSS)-induced colitis model evaluate altered 5-ASA. Results changed over time SPF At genus level, relative abundance Allobaculum increased significantly females compared (corrected p < 0.05). same tendency was observed counterparts. mRNA expression IL-10 IL-22 counterparts (p 0.05 sexes). similar between pups, suggesting vertically transmitted group. CD4+RORgt+ MLN those 0.01). TGF-b, claudin-2 claudin-3 0.001). inflammation induced DSS milder (Figure 1). Conclusion Orally-administered affecting host system leading less susceptibility DSS-induced colitis. Alteration could be part