The Effect And Underlying Mechanism Of Soluble Diet Fiber And Fecal Microbiota Transplantation On Ulcerative Colitis

Inflammatory bowel disease (IBD) is a chronic relapsing disease, including ulcerative colitis (UC) and Crohn’s disease (CD). Although the etiology of IBD is unknown, but more and more evidence show that the inappropriate immune response to intestinal commensal bacteria leading to dysbiosis causes IBD. Has yet not to determine the specific one or more pathogens as the cause of IBD, but literatures confirm the changes of diversity of the intestinal flora, such as reduced Bifidobacterium and Lactobacillus but increased mucosal bacteria.Based on the current awareness of changes in the intestinal flora in IBD, fecal microbiota transplantation (FMT) was proposed recently years to rebuild the balance as a new treatment. Thomas J et reported six patients with UC were cured by FMT. Martin J’s study confirmed recipients’flora can be maintained for 24 weeks after FMT. Kahn reported patients with UC were willing to accept FMT. However, recent studies showed that fecal bacteria of patients can not consistent with donor’s for a long term after transplantation.Maintaining the diversity of flora in a long time so that well controlled the disease become the breakthrough of fecal microbiota transplantation in the treatment of UC.Pectin is a soluble dietary fiber (DF), can be fermentated by gut flora into short chain fatty acids (SCFA) which supply the energy for epithelial cells, regulate intestinal PH and join effort in immune regulation with intestinal lymphoid tissue. Previous studies showed SCFA can influence regulatory T cells, but no studies have confirmed whether dietary fiber could adjusted the flora colonization ability in patients with IBD. We conceive that pectin by some mechanism to promote the migration of probiotics in intestine engraftment, reduce pathogenic agents’ adhesion of intestinal mucosa and to maintain intestinal flora diversity in a long time.2. Purpose:To compare the different effect of co-transplantation of dietary fiber and FMT, simple FMT to patients with UC through prospective, randomized, single-blind, parallel-group, single-center clinical study. To observe different interventions’effects on bowel flora changes, adjustment and the maintenance time; Observe the relationship of gut microbiota changes and the disease activity to further clarify the link between the bowel immune and the intestinal flora, to explore the mechanism of dietary fiber and bacteria group therapy in UC and lay the theoretical foundation for the clinical application of specific flora and dietary fiber in the treatment of UC.PART ⅠThe effect of fecal microbiota transplantation on ulcerative colitisObjective:Make out the efficacy and safety of fecal microbiota transplantation in treating UC.Method:21 patients with mild-to-moderate (Mayo score 2-10) UC finished fecal mircobiota transplantation via colonoscopy. Stable dosage drug unchanged before and after transplantation. The transplant volume was 300 ml with the whole flora from 60g fresh stool of standard donor. Record and compare Mayo score, IBDQ, CRP, ESR, UCEIS and FC before transplantation and 4 weeks,12 weeks after transplantation. Adverse effect was also recorded.Results:All 21 patients completed fecal mircobiota transplantation. No significant changes in the ESR and CRP before and after transplantation.But IBDQ, FC and Mayo score decreased significantly after transplantation(P<0.05). Response rate and disease remission rate were 71.43% and 38.10% respectively 4 weeks after transplantation. They were 66.67% and 33.33% 12 weeks after transplantation. The incidence of adverse reactions was 14.29%.But all were mild adverse reactions needing no special treatment. Intestinal flora diversity increased significantly after transplantation (P< 0.05).Conclusion:Fecal microbiota transplantation is safe and effective in treating mild-to-moderate ulcerative colitis. It can also increase the intestinal flora diversity.PART IIThe effect of soluble diet fiber and fecal microbiota transplantation on ulcerative colitisObjective:Observe the effect of soluble dietary fiber combined with FMT on UC and compare with FMT alone in the treatment effect.Method:Mild-to-moderate ulcerative colitis patients were randomly divided into fecal microbiota transplantation group (FMT n= 10) and soluble dietary fiber with fecal microbiota transplantation group (FMTP n= 10). Both groups accepted colonoscopy for infusion the bacterial liquid with volume 300 ml from 60g fresh stool of standard donor. Patients in the FMTP group take pectin orally for consecutive five days,20 g/day. Record and compare Mayo score, IBDQ, CRP, ESR, UCEIS and FC before transplantation and 4 weeks,12 weeks after transplantation. Gut flora changes was also analyzed.Results:Compared two groups, Mayo score decreased significantly in FMTP group 4 weeks and 12 weeks after transplantation. But there is no significant difference in CRP,ESR,FC and IBDQ. Flora diversity were the same between the two groups, but flora composition in FMTP group was closer to the donor. Flora stability was also better than FMT group. Probiotic bacteria was higher in the FMTP group (P<0.05) after transplantation. These may account for lower Mayo score in FMTP group 12 weeks after transplantation. Butyric acid bacteria content with no difference.Conclusion:Mayo score remained lower in FMTP group than in FMT group 12 weeks after transplantation. This may because soluble dietary fiber can keep intestinal flora diversity for a longer time and increase content of probiotics.PART ⅢMechanism of soluble dietary fiber in increasing the effect of fecal microbiota transplantationObjective:To explore the possible mechanism of soluble dietary fiber in increasing the effect of fecal microbiota transplantation.Method:Collect stool specimens before transplantation and 4 weeks,12 weeks after transplantation of patients in part II. Endoscopic biopsy specimens before transplantation and 12 weeks after transplantation were also collected. Stool specimens used for detecting short-chain fatty acids and biopsy specimens for histopathology, immunofluorescence (HDAC) and qPCR of cytokines (IL-1, IL-6, TNF-a, IL-10) detection.Results:Overall, short chain fatty acids in feces raised significantly after transplantation (P<0.05). Proinflammatory cytokines such as TNF-a, IL-6, IL-1 decreased significantly after transplantation, but anti-inflammatory cytokines IL-10 raised significantly (P<0.05). Comparison between the two groups, propionic acid in feces is higher in FMTP group than the FMT group after transplantation (P<0.05), butyric acid and acetic acid have no difference between the two groups. FMTP was associated with a significant reduction of IL-6 (P<0.05), but IL-10, TNF-a, IL-1 have no significant difference. Histopathology confirmed HDAC expression and inflammatory response decreased in FMTP group.Conclusion:Short-chain fatty acids produced by commensal bacteria from soluble dietary fiber as inhibitor of HDAC, reduced proinflammatory cytokine such as IL-6, and afterwards reduced tissue inflammation reaction.