There are provided novel synthetic stool preparations comprising bacteria isolated from a fecal sample from a healthy donor. The synthetic stool preparations are used for treating disorders of the gastrointestinal tract, including dysbiosis, Clostridium difficile infection and recurrent Clostridium difficile infection, prevention of recurrence of Clostridium difficile infection, treatment of Crohn's disease, ulcerative colitis, irritable bowel syndrome, inflammatory bowel disease, and diverticular disease, and treatment of food poisoning such as salmonella. Methods of preparation and methods of use of the synthetic stool preparations are also provided.