P834 Effects of short-chain fatty acids supplementation on gut inflammation in DSS-induced murine colitis model
Abstract Background Short-chain fatty acids (SCFAs) play an important role in maintaining gut homeostasis. However, inconclusive results exist whether administration of SCFAs ameliorates gut inflammation in patients with inflammatory bowel disease. We aimed to evaluate the effects of butyrate or mixture of SCFAs on gut inflammation in the dextran sulphate sodium (DSS)-induced murine colitis model. Methods Following oral treatment with 150 mM sodium butyrate or mixture of SCFAs (67.5 mM acetate, 40 mM butyrate, 25.9 mM propionate) for 2 weeks, acute colitis was induced in the C57BL/6 mice by adding 2% DSS to the drinking water for 7 days. Clinical activities including weight change and histologic findings of colonic segments were examined. Flow cytometry analysis was performed for analyzing regulatory T cells in the colonic lamina propria. To characterise the change of intestinal microbiota, high throughput Illumina MiSeq sequencing for sequential faces were performed. Results There were no significant differences in weight change, colonic length, and histological inflammation score between the DSS group, butyrate group, and SCFA mixture group. However, fluorescence activated cell sorter (FACS) analysis revealed that the expression of CD4+Foxp3+ regulatory T cells were increased in the butyrate and SCFA mixture groups than in the DSS group. Metagenomic sequencing analysis demonstrated that gut microbial profiles of the butyrate and SCFA mixture groups were significantly different from those of the control and DSS groups in PCoA. The relative abundances of the phyla Verrucomicrobia and Proteobacteria, species Akkermansia muciniphila and Escherichia fergusonii were increased in the butyrate and SCFA mixture groups than control and DSS groups. Conclusion Oral administration of butyrate or mixture of SCFAs resulted in changes in the gut microbial profiles and increased regulatory T cell expressions. However, gut inflammation was not alleviated by butyrate or SCFA supplementation in the DSS-induced murine colitis model.
