Pectin is a soluble dietary fiber (DF), produced by the gut flora after a series of fermentation with many metabolites such as short chain fatty acids (SCFA) which supply the energy for epithelial cells, regulate intestinal PH and intestinal motility and join effort in immune regulation with intestinal lymphoid tissue. Previous studies showed that: water-soluble dietary fiber with the action of intestinal flora can cut the inflammatory cytokines, prevent inflammation and induce regulatory T cells, but the type and dose of dietary fiber used were different in different studies, and 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, cut inflammation, and to maintain intestinal flora diversity and steady state in a long time, and than achieve the goal of continue to ease IBD.