Described herein are methods and compositions for the use of treating and/or preventing Clostridium difficile infections, including recurrent C. difficile infections, in a subject. Aspects of the technology relate to administering to a subject in need thereof a composition comprising a defined therapeutic microbiota comprising, e.g. Clostridial species. Also described herein are biomarker profiles, including a biomarker profile comprising two groups of Clostridial species, that is predictive of the likelihood of recurrent C. difficile infection and/or susceptibility to initial C. difficile infection.