 The host gastrointestinal microbiota is significantly influenced by antibiotic treatment which might favor Clostridium difficile infection CDI, a frequent cause of community- and hospital-acquired, potentially life-threatening diarrhoea. CDI is followed by recurrence in 19-35 of patients despite adequate first line antimicrobial therapy. Currently there is no standardized therapy of recurrent or refractory CDI, but recent studies show remarkable effects of fecal microbiota transplantation FMT. 