Purpose of review 

Nosocomial infections are common and are associated with considerable morbidity and mortality. The continuing evolution of multidrug resistant pathogens and ineffective therapy for the infections they cause has stimulated interest in the potential of probiotic products to prevent nosocomial infections. Probiotics are viable microorganisms that colonize the host and exert antibacterial and immunomodulatory effects. This article will review the current evidence for probiotics in preventing nosocomial infections, particularly pneumonia in a diverse population of critically ill patients.

Recent findings 

Currently, there are insufficient data to conclusively determine whether probiotics are beneficial in the prevention of nosocomial infections, particularly nosocomial pneumonia. Most of the current literature is limited by poor trial design, inadequate blinding, small study samples, and poorly defined endpoints.

Summary 

Probiotic products reduce pathogenic colonization of the host. Despite the theoretical plausibility, there is currently insufficient evidence that probiotic products reduce the incidence of nosocomial pneumonia. Large, multicenter, randomized clinical trials utilizing a rigorous, invasive diagnostic approach to nosocomial pneumonia need to be performed to prospectively evaluate the utility of probiotic products. In addition, bench research needs to be performed to select the most appropriate probiotic formulation for different clinical applications.