Faecalibacterium Prausnitzii Supernatant Regulate Macrophages To Decrease Colitis In Mice Induced By Dextran Sulfate Sodium

Background:Monocytes and macrophages can regulate different inflammatory reactions,Monocytes and macrophages can regulate gut inflammatory reactions in inflammatory bowel disease(IBD).Aims:To investigate the effect and mechanism of Faecalibacterium prausnitzii(F.prausnitzii)supernatant on dextran sulfate sodium(DSS)induced colitis by regulating monocytes and macrophagesMethods:Thity C57BL/6 mice were randomly divided into the normal control group,colitis group,and F.prausnitzii supernatant-treated group(n=10 in each group).The colitis group drank 4.5%DSS for seven days.The F.prausnitzii supernatant-treated group was treated to F.prausnitzii supernatant at the same time drinking 4.5%DSS for seven days.The weight loss,feces situation and the histopathological damage of colon tissue were recorded.The proportion of monocytes and macrophages of spleen and colon was detected by flow cytometry.The peripheral blood serum level of IL-4,IL-6,IL-10,IFN-y and CCL2 was measured by multi-analyte flow assay kit.Results:Compared to the normal group,the colitis group was more weight losing,obvious bloody stool,shorten colon length and higher colonic histopathological score.The index mentioned above in F.supernatant-treated group was obviously improved than that in colitis group.The proportion of CD11b+LY6C in spleen and intestinal lamina propria in colitis group was higher than that in F.prausnitzii supernatant-treated group.,CD11b+LY6Chigh proinflammatory monocytes proportion of colitis group was higher than that of F.prausnitzii supernatant-treated group.The F4/80 monocyte in spleen was higher in the F.prausnitzii supernatant-treated group than that in colitis group.,however,there was no statistical significance in the intestinal lamina propria.The CDl1bhigh+F4/80mid macrophages proportion of spleen in colitis group was lower than that in normal group and F.prausnitzii supernatant-treated group,but the macrophages of the intestinal lamina propria in colitis group were higher than that in normal group and F.prausnitzii supernatant treated group.The CDllbneg+F4/80high macrophages n spleen and intestinal lamina propria were lower in colitis group than that in normal group and F.prausnitzii supernatant-treated group.The M1 macrophage proportion of spleen and intestinal laminal propria in colitis group were higher than that in normal group and F.prausnitzii supernatant-treated group,and the M2 macrophage proportion of spleen has no statistical significance,but in intestinal laminal propria the M2 macrophages were extremely higher in F.prausnitzii supernatant-treated group than that in other groups.The peripheral blood serum levels of IL-4 and IL-10 in F.prausnitzii supernatant-treated group were higher than that in colitis group.The levels of IL-6,IFN-y,CCL2 in colitis group were higher than that in F.prausnitzii supernatant-treated group.Conclusion:The F.prausnitzii supernatant can reduce the proinflammatory monocytes and proinflammatory cytokines and promote the macrophages of spleen to migrate to intestinal lamina propria to accelerate the M2 macrophages of intestinal lamina propria.Meanwhile,F.prausnitzii supernatant could increase the cytokins levels of IL-4 and IL-10 in peripheral blood and reduce the levels of IL-6?IFN-??CCL2.