Probiotics in GI diseases

Probiotics are living organisms, which upon ingestion in certain numbers, exert health benefits beyond inherent basic nutrition. Probiotics have been studied in a variety of GI diseases, and are an appealing concept given their favourable safety profiles. Current data on the use of probiotic therapy in GI diseases are reviewed. The rationale for using probiotics in IBD is based on convincing evidence that implicates intestinal bacteria in the pathogenesis of the disease. VSL#3, a highly concentrated cocktail of probiotics, has been shown to be effective in the prevention of pouchitis onset and relapses. Results from the use of probiotics in ulcerative colitis have been promising, while results in Crohn's disease are not yet clear. Placebo-controlled trials indicated that lactobacilli have a suppressive effect on Helicobacter pylori infection. Although some studies reported improvement in H. pylori eradication, others failed to confirm this. The clear delineation of a post-infective variety of irritable bowel syndrome (IBS), suggests a role for a dysfunctional relationship between the indigenous flora and the host in IBS and, accordingly, provides a clear rationale for the use of probiotics in this disorder. Probiotics may have a role in alleviating some of the symptoms of IBS, but results from controlled trials are controversial. Future studies are needed, in particular larger studies of longer duration with greater methodological rigor. Controlled trials support the use of Lactobacillus rhamnosus GG and Saccharomyces boulardii for the prevention of antibiotic-associated diarrhoea, and have demonstrated the effectiveness of S. boulardii as adjunctive therapy in Clostridium difficile disease.