Probiotics for prevention of Clostridium difficile infection

Purpose of review Probiotics may prevent Clostridium difficile infection (CDI), a leading healthcare-associated infection in the United States. However, prior studies were limited by heterogeneity in products and patient populations. Recent clinical evidence and new approaches to probiotic development are reviewed. Recent findings Probiotic use may reduce incident CDI in high-risk populations by as much as 50%, though prior clinical trials have yielded conflicting results. Combining probiotics with prebiotics improves growth and engraftment in the host. Bacillus clausii and Lactobacillus reuteri secrete compounds that directly inhibit C. difficile. Organisms that produce secondary bile acids, such as Clostridium scindens, enhance C. difficile colonization resistance. Nontoxigenic C. difficile, which provides nutritional niche competition, may prevent CDI. Refinements to fecal microbiota transplantation (FMT) blur the line between probiotics and FMT. These include a quality-controlled stool product (RBX2660), purified Firmicutes spores (SER-109) and sterile fecal filtrate. Bacteriophages may treat CDI but have unknown safety and efficacy in humans. Summary There have been a number of advances in probiotics and our understanding of their role in prevention of CDI, but a number of important safety and efficacy questions remain. An improved understanding of the native microbiota structure and function will allow for continued development of rationally designed probiotic therapy to provide enhanced protection against CDI.