Transplanting the intestinal microbiota (via stool) from a healthy subject with normal bowel function to a patient – known as fecal microbiota transplantation (fecal microbiota transplantation) – was first applied by the Chinese physician Ge Hong in the fourth century to treat severe diarrhea and malaria. In the present era, fecal microbiota transplantation represents an effective treatment for Clostridium difficile infection (CDI) and is also a promising discovery for other diseases.