Probiotics for the Prevention of Clostridium difficile-associated Diarrhea

A recent systematic review article, which included 31 randomized trials, was published in Cochrane Database Syst Rev. The primary objectives were to evaluate the safety and efficacy of probiotics for preventing Clostridium difficile-associated diarrhea (CDAC) or C. difficile infection in children and adults. Other side effects associated with antibiotics intake were also evaluated.


Twenty-three trials assessed the effectiveness of probiotics in preventing CDAD in participants taking antibiotics. The results suggest that when probiotics are taken in conjunction with antibiotics, there is a 64% reduction in the risk of developing CDAD. Side effects were assessed in 26 trials and the results suggest that probiotics decrease the risk of developing side effects such as abdominal cramping, nausea, fever, soft stools, flatulence, and taste disturbance. With respect to the incidence of C. difficile infection, results from the 13 trials did not show a statistically significant reduction.


One of the roles of the intestinal microflora is to serve as a protective barrier and resist the colonization of intestinal pathogens. Under normal conditions, the microflora exists in a balanced ecosystem where beneficial microorganisms inhibit pathogens, support intestinal health and enhance immune response. The intestinal microbial ecosystem balance can be disrupted by the intake of antibiotics and dangerous pathogens, such as Clostridium difficile, can then colonize and contribute to a range of symptoms such as diarrhea.

Probiotics are microorganisms that can help protect and maintain a balanced intestinal microflora. Furthermore, they can also assist in restoring the disrupted intestinal microflora, enhancing immune responses and inhibiting or clearing pathogens and their toxins. Saccharomyces boulardii is one of the most widely used microorganisms for preventing CDAC. 

Review title/source: Probiotics for the prevention of Clostridium difficile-associated diarrhea in adults and children. Cochrane Database of Systematic Reviews 2013, Issue 5. Art. No.: CD006095