CD4 and clostridium difficile infection: Of these 259, 108 patients were excluded due to impaired intestinal integrity (85 patients), immunocompromised status (6 patients with a history of organ transplant, 4 patients with a history of hematologic malignancy, 1 patient with ANC <500 cells/μL and 1 patient with a history of HIV and CD4 <200 cells/μL), CDI in the past 60 days prior to admission (2 patients) and active community-associated C. difficile infection (CA-CDI) on admission (9 patients), leaving 151 eligible patients who did not receive BioK+.