Ulcerative colitis (UC) is one of the two main forms of inflammatory bowel disease. UC is associated with high morbidity and incurs significant social, commercial and NHS costs. For a variety of reasons, many patients are refractile to standard therapies, which often have undesirable side-effects. However, an inexpensive and non-toxic treatment based on the synbiotic concept may prove to be effective in these individuals. A synbiotic is a mixture of a probiotic (a live microorganism) and a prebiotic, which is a carbohydrate that serves as a food source for the probiotic, allowing it to grow better in the gut. The aim of this study is to determine whether a synbiotic comprised of fructooligosaccharides and inulin, together with a bifidobacterial probiotic (Bifidobacterium longum), that we have previously shown to reduce inflammatory processes in the gut wall (mucosa) in a short-term pilot trial, can colonise the bowel, reduce mucosal inflammation, and induce remission in UC patients with active disease. It is planned to establish a double-blinded, controlled, randomised investigation involving 46 patients for six months. If the results from our pilot study can be reproduced and maintained in a long-term investigation, the synbiotic could become available very quickly, and would provide an inexpensive and effective treatment for UC, making a significant contribution to relieving the clinical and financial burdens of this disease.