a1 Digestive System Research Unit, University Hospital Vall d'Hebron, Passeig Vall d'Hebron 119–129, Barcelona, 08035, Spain
A large and diverse variety of bacteria have evolved and adapted to live in the human intestinal habitat in a symbiotic arrangement that influences both physiology and pathology in the host. Symbiosis between host and flora can be optimised by prebiotics. Inulin-type fructans have been shown to improve the metabolic functions of the commensal flora. Clinical and experimental data suggest that they also improve the gut mucosal barrier. Furthermore, modulation of the trophic functions of the flora by these prebiotics could help in the prevention of inflammatory bowel diseases. The anti-inflammatory effects of inulin or oligofructose have been assessed in the rat model of distal colitis induced by dextran sodium sulphate, which histologically resembles human ulcerative colitis, and in the trinitrobenzene sulphonic acid model that resembles human Crohn's disease. Both inulin and oligofructose stimulate colonic production of SCFA and favour the growth of indigenous lactobacilli and/or bifidobacteria. These effects are associated with reduced mucosal inflammation and decreased mucosal lesion scores. Inulin has also been tested in a placebo-controlled clinical trial in patients with relapsing pouchitis. Treatment reduced endoscopic and histological parameters of inflammation of the pouch mucosa. Inulin and oligofructose may offer an opportunity to prevent chronic inflammatory intestinal disorders, and this potential should be tested in further clinical studies.