Two distinct long-term (one year), large-scale, multi-centered, randomised, double blind, placebo-controlled probiotic-based clinical trials of remission maintenance within a subset of the European Union population suffering from Inflammatory Bowel Disease (IBD) will be performed. In former EC-funded studies, two probiotic bacterial strains have been isolated, characterised and demonstrated to be safe and efficient.

• The efficacy of probiotic micro-organisms, administered as fermented milk products, in maintaining remission of inflammatory bowel disease (IBD) - Crohn's disease and ulcerative colitis - will be assessed.
• The PROGID partners will establish a repository of biological samples (blood, saliva, and faeces) isolated from a subset of the EU population suffering from Crohn's disease or ulcerative colitis. This material may provide information from which the effects mediating probiotic effects may be elucidated.

• Assessment of the efficacy of 2 previously-isolated and well-characterised probiotic micro-organisms in the treatment of European patients with inflammatory bowel disease (i.e., Crohn's disease or ulcerative colitis);
• Critical determination of the role of enteric flora in initiating, or promoting, inflammatory events in the pathogenesis of inflammatory bowel disease;
• Characterisation of the population dynamics of microbial flora associated with inflammatory bowel disease through both conventional microbiological techniques and existing innovative molecular biology-based technologies, which will also identify the major unculturable groups of gastrointestinal microbial flora.
• Determination of the effects of consumption of the two selected probiotic bacteria on the host response.