Efficacy and Safety of BIO-K + CL1285 in Prevention of Antibiotic-associated Diarrhea in Hospitalized Adult Patients

Inclusion Criteria: * presenting to the Emergency Room and considered for admission to hospital for a minimum of 12 hours and requiring antibiotic administration for the treatment of a suspected or proven bacterial infection OR a hospitalized patient developing a suspected or proven nosocomial infection OR an external patient that come to the hospital for repeated visits to receive his intravenous antibiotic therapy for the treatment of a suspected or proven bacterial infection. The external patients on oral antibiotics that come to the hospital for repeated visits to receive any other treatments requiring a hospital stay of more than one hour will also be included. * Hospital employee on antibiotics can also be included in the study * having received less than 24 hours of antibiotic therapy; * requiring a minimum of 3 days and a maximum of 14 days antibiotic administration Informed consent must be obtained in writing for all subjects at enrollment into the study Exclusion Criteria: Subjects presenting with any of the following will not be included in the study: * active diarrhea; * a history of daily consumption of fermented milk and/or yogurt; * intolerance to lactose; * pregnant/breastfeeding women; * an active, non controlled intestinal disease such as Crohn's Disease or ulcerative colitis; * ileostomy, jejunostomy or colostomy; * immunosuppressed state; * a previous documented C. difficile infection in the three months prior to study initiation; * active radiotherapy or chemotherapy; * recent (\< 6 months) or planned bone marrow graft or organ transplant; * antibiotic therapy in the fourteen days prior to study initiation; * the planned administration of metronidazole (alone or in combination) or vancomycin monotherapy for the treatment of an infection; * mental or other conditions, or language barriers rendering the subject unable to understand the nature, scope, and possible consequences of the study or complete the self-administered questionnaires; * subject unlikely to comply with protocol, e.g., uncooperative attitude, inability to return for follow-up visits, and unlikelihood of completing the study. Post-enrollment exclusion criteria include fermented milk and/or yogurt consumption during the study period and two consecutive missed dose of study product.