Probiotics and Fecal Microbiota Transplant for Primary and Secondary Prevention of Clostridium difficile Infection

Clostridium difficile infection (CDI) is the most common cause of nosocomial diarrhea and is associated with an increased risk of mortality. The use of probiotics and fecal microbiota transplantation (FMT) has been studied to reduce the incidence and severity of this infection, but variable efficacy and safety data have been reported. Probiotics are hypothesized to be effective in the management of CDI through a number of mechanisms that include maintenance of normal gastrointestinal flora, antimicrobial and antitoxin properties, and immunomodulatory effects. Despite promising results in small trials and meta-analyses, prospective, randomized, controlled trials have not demonstrated probiotics to be effective in the primary prevention of C. difficile-associated diarrhea (CDAD). Probiotics may be effective for secondary prevention in patients with recurrent CDI, but guidelines acknowledge the lack of compelling evidence. Trials are limited by the use of varying types of strains, numbers of strains, and doses of probiotics, as well the definitions of CDI and CDAD. FMT has been proposed as a method for restoring gut microbiota and has been shown to significantly increase the rate of cure in patients with recurrent CDI. Current studies have demonstrated minimal adverse effects, with no reports of transmission of infectious diseases; however, the optimal delivery method, sample preparation, and donor selection remain unclear. In this review, findings from recent literature are highlighted, and guideline recommendations for the use of these agents in the primary and secondary prevention of CDI are summarized.