title: The fascination with probiotics for Clostridium difficile infection: lack of evidence for prophylactic or therapeutic efficacy.
abstract: BACKGROUND
  The association of Clostridium difficile infection (CDI) with antecedent antibiotic use suggests that perturbation of normal intestinal flora is an important inciting factor. Therefore, the use of probiotics for the prevention and/or therapy of CDI is considered to be theoretically effective.
  
  
  METHODS
  A non-systematic review of the literature evaluating the prophylactic and therapeutic efficacy of oral bacterial or yeast products for CDI, as well as the "quality control" and deleterious effects of these agents.
  
  
  RESULTS
  There is no convincing literature which supports the use of bacterial/yeast products to prevent CDI. There is one prophylactic study from the United Kingdom which showed efficacy, but it has been widely criticized as flawed or not generalizable. One other small case-series described the efficacy of Saccharomyces boulardii in preventing CDI relapse, but only in a subset of patients. Many bacterial/yeast products do not contain what they are purported to contain, and may contain other bacterial/fungal constituents not listed on the label. S. boulardii preparations may predispose to bloodstream infections in recipients, and have been associated with fungemia in contiguous patients when prepared at the bedside in intensive care settings.
  
  
  CONCLUSIONS
  There is no persuasive evidence to support the use of bacterial/yeast products for the prevention or treatment of CDI. Oral preparations may not contain what is indicated on the label. Widespread use of some products may lead to bloodstream infections in susceptible individuals, and careless use of S. boulardii in an intensive care setting may place other patients at risk. At the present time, oral bacterial/yeast products do not have a role in the prevention or therapy of CDI.
authors.affiliation: SMBD-Jewish General Hospital, McGill University, 3755 Cote-Ste-Catherine, Montreal, Quebec, H3T 1E2, Canada. mmiller@lab.jgh.mcgill.ca
authors.forename: Mark
authors.initials: M
authors.lastname: Miller
mesh_terms: D001644:Bifidobacterium; D003015:Clostridium Infections / Q000382:microbiology / Q000517:prevention & control / Q000628:therapy; D004761:Enterocolitis, Pseudomembranous / Q000382:microbiology / Q000517:prevention & control / Q000628:therapy; D006801:Humans; D007778:Lactobacillus; D015201:Meta-Analysis as Topic; D019936:Probiotics / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use*; D011786:Quality Control; D016032:Randomized Controlled Trials as Topic; D012440:Saccharomyces; D016896:Treatment Outcome