Bacterial spores in capsules taken by mouth can prevent recurrent C. difficile infection, results from a preliminary study suggest.
Clostridium difficile is the most common hospital-acquired infection in the United States and can cause persistent, sometimes life-threatening diarrhea. Fecal microbiota transplant has shown promise in many clinical studies as a treatment for C. difficile, but uncertainty has surrounded how such transplants should be regulated and standardized. Also, the still-investigational procedure is often performed by colonoscopy, which may be difficult for some patients to tolerate.
The capsule study, published Monday in Journal of Infectious Diseases, represents an important step in moving away from fecal microbiota transplant as a treatment for C. difficile, says Colleen Kraft, MD, assistant professor of pathology and laboratory medicine and medicine (infectious diseases) at Emory University School of Medicine.
Kraft and Tanvi Dhere, MD, assistant professor of medicine (digestive diseases) have led development of the fecal microbiota transplant program at Emory. They are authors on the capsule study, along with investigators from Mayo Clinic, Massachusetts General Hospital, Miriam Hospital (Rhode Island), and Seres Therapeutics, the study sponsor.
While this study involving 30 patients did not include a control group, the reported effectiveness of 96.7 percent compares favorably to published results on antibiotic treatment of C. difficile infection or fecal microbial transplant.
The bacterial spores are obtained by treating stool samples from healthy, screened donors with ethanol, and separating them away from other microbes including potential pathogens. The JID paper says the capsules contain about 50 species of Firmicutes spores. All of the 30 patients in the study received the capsules – the first 15 received a higher dose. At the end of the eight-week study period, investigators reported they could detect not only establishment of the bacterial species contained in the capsules, but also a return of other beneficial species not found in the capsules.
Seres is now conducting a phase 2 study of the same capsules, in which Emory is a participating clinical site .