The intestinal microbiota play a pivotal role in the inflammation associated with Crohn’s disease through their interaction with the mucosal immune system. Some bifidobacteria species are immunoregulatory and induce increased dendritic cell interleukin 10 (IL-10) release in vitro. Fructooligosaccharides (FOS) increase faecal and mucosal bifidobacteria in healthy volunteers. The aim of this study was to assess the effect of FOS administration on disease activity, bifidobacteria concentrations, and mucosal dendritic cell function in patients with moderately active Crohn’s disease.

Crohn's disease is an inflammatory illness in which the immune response against gut microorganisms is believed to drive an abnormal immune response. Consequently, modification of mucosal bacterial communities, and the immune effects they elicit, might be used to modify the disease state. A randomized, double-blind placebo-controlled trial was conducted involving 35 patients with active Crohn's disease, using a synbiotic comprising Bifidobacterium longum and Synergy 1.