The mechanisms and safety of probiotics against toxigenic clostridium difficile.

INTRODUCTION: Toxigenic Clostridium difficile (C. difficile) is the main cause of antibiotic-associated diarrhea and can induce pseudomembranous colitis and infrequent toxic megacolon, which are potentially fatal. The standard antibiotic therapy for C. difficile infection (CDI) is limited by antibiotics' broad spectrum and further disruptive effects on indigenous microbiota. Probiotics may offer a prospective and alternative strategy for the prevention and treatment of CDI. AREAS COVERED: In this article, the mechanisms implying the probiotic effect against C. difficile and the safety profile highlighting the patient groups with inappropriate application of probiotics were reviewed from 2015 to 2020. EXPERT OPINION: Although many strains with ability against C. difficile have been reported, the usage of probiotics for CDI prevention and/or treatment is scarce since the number of clinical trials is not sufficient to prove probiotics' efficacy and safety in CDI treatment, especially for premature infant and immunocompromised patient. Especially, there are few well-defined clinical studies supporting safety of probiotics for CDI. A few strains from Lactobacillus and Saccharomyces genus have been studied more extensively than other probiotic strains through clinical trials for CDI. Thus, more clinical intervention studies regarding the benefit and the comprehensive safety assessments of probiotics for CDI are needed.