Effects Of Berberine On Intestinal Microflora And Immunity In Rats With Irritable Bowel Syndrome

Objectives: We are aimed to demonstrate the efficacy of berberine in the treatment of IBS,and study the effect of berberine on the regulation of intestinal flora and immune function in a rat modal of IBS.Methods: We made a rat modal of IBS via chronic water avoidance stressors,and the rats were treated with low-dose of berberine,high-dose of berberine and rifaximin respectively for 10 days.Then these rats were killed by breaking neck,and then experimental tests were performed.(1)Record the △EMG,take distal ileum tissues from each group for pathological assessment by HE staining and measure the expression level of CRF by immunohistochemistry.(2)Illumina sequencing were used to analyze the changes of population abundance,biodiversity and colony structure of the intestinal flora in the terminal ileum.(3)Take rat spleens and detect the Treg/Th17 ratio by flow cytometry,evaluated the expression level of cytokine IL-17,IL-10,IL-23 and IL-6 in rat distal ileum tissues by qRT-PCR.Detect the expression of STAT3 and p-STAT3 in the distal ileum tissue of rat by western blot test.Results: The IBS model was established successfully.Berberine can significantly reduce the visceral sensitivity,prevent intestinal inflammation,and reduce the expression of intestinal CRF in IBS rats.(2)High-dose of berberine can remarkably reduce the abundance and diversity of intestinal flora in IBS rats and increase the proportion of Lctobacteriaceae,while Clostridium,Turicibacteraceae bacteria and Enterobacteriaceae were particularly inhibited.But low-dose of berberine could not increase the proportion of Lactobacillus,and had little effect on the abundance and diversity of intestinal flora in IBS rats.(3)High-dose of berberine could down-regulate the Th17 ratio but improve the proportion of Tregs of spleen lymphocytes in IBS rats;and obviously decease the expression of proinflammatory cytokine IL-6,IL-17 and IL-23 in the distal ileum tissues,while elevating of anti-inflammatory cytokine IL-10,meanwhile high-dose of berberine could also remarkably down regulate the expression of STAT3 and p-STAT3 in the terminal ileum of IBS rats.The effect of low-dose of berberine on the immunoregulation in IBS rats was not significant.(4)The therapeutic effect of high dose of berberine group on IBS rats was evidently superior to that of low dose group.Conclusion: Berberine can effectively prevent the visceral hyperalgesia and intestinal inflammatory response,reduce the expression of CRF in intestinal tract,change the diversity of intestinal flora and the colony structure,and regulate the immune function of IBS rats.The therapeutic effect of high dose of berberine on IBS rats was evidently superior to that of low dose group.