Pomegranate extract specifically inhibits Clostridium difficile growth and toxin production without disturbing the beneficial bacteria in vitro Murugapillai Rathinam Sukumar, Brigitte König Institute for Medical Microbiology and Epidemiology of Infectious Diseases, Leipzig University Hospital, Leipzig, Germany Objective: The aim of this study was to assess the pomegranate juice against the growth and toxin production of multidrug-resistant Clostridium difficile hypervirulent strain NAP1/027/BI and also against the growth of beneficial bacteria to prevent or suppress C. difficile infection (CDI).Materials and methods: Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were taken as parameters for the assessment of antimicrobial property of the pomegranate juice. Four different C. difficile hypervirulent strains NAP1/027/BI, Lactococcus lactis spp., Lactobacillus casei, and Bifidobacterium animalis were subjected to the broth dilution method to determine the MIC and MBC. Enzyme-linked immunosorbent assay (ELISA) was performed to determine clostridial toxin B (TcdB) production in the presence of pomegranate juice.Results: The MIC and MBC of pomegranate juice containing punicalagin were found to be 390 µg/mL for all C. difficile hypervirulent strain NAP1/027/BI, and the growth of L. lactis spp., L. casei, and B. animalis was not inhibited. Pomegranate juice reduced TcdB production in C. difficile hypervirulent strain NAP1/027/BI.Conclusion: This study highlights the potential of pomegranate juice to reduce CDI without affecting the beneficial bacteria. Pomegranate juice may be a useful antimicrobial agent to prevent or suppress CDI, avoiding the use of antibiotics. Keywords: Clostridium difficile, pomegranate juice, antimicrobial agent, CDI