Antibiotic-associated diarrhea (AAD) and particularly Clostridium difficile-Infection (CDI) are the most common causes of healthcare associated infectious diarrhea. In light of the results obtained in a limited number of randomized clinical trials in subjects with AAD and CDI in comparison with the widespread occurrence of these diseases, it is felt that the addition of a well-controlled clinical trial in a western environment would add value to support the use of a specific probiotic to counteract these diseases.