Dr. Thomas Louie, an infectious disease specialist at the University of Calgary, prepares stool pills in his lab in Calgary, Alberta, Canada on Sept. 26. Donor stool, usually from a relative, is processed in the lab to extract the bacteria and clean it. It is packed into triple-coated gel capsules so they won't dissolve until they reach the intestines of an ill patient.
(Photo: Jeff McIntosh AP)
SAN FRANCISCO - A "poop pill" may hold the key to healing an intractable infection that kills 14,000 Americans and sickens more than a half-million each year.
A Canadian team is testing the idea on patients with multiple infections of Clostridium difficile that did not respond to antibiotic treatments. The patients swallowed capsules containing fecal microbes from a family member.
Only one of the patients in the ongoing trial has had a recurrence, compared with an 80% rate in patients who have had multiple bouts of the disease, according to the Centers for Disease Control and Prevention.
"That one patient, in June, had a recurrence after being treated with antibiotics for a separate infection," said Thomas Louie, a professor of medicine at the University of Calgary in Canada and lead author of the study. He presented it at a conference on infectious diseases in San Francisco on Thursday.
"I think in some ways the 'ick' factor is something we got out of the schoolyard," Louie said. "It's really quite primordial, but we just need to get over it."
Clostridium difficile is a bacterial infection that can cause diarrhea and in some cases a life-threatening inflammation of the colon. It typically occurs after patients have taken antibiotics to treat another infection.
The illness happens when the healthy microbes in the patients' intestines are killed by the antibiotics, allowing the C. diff bacteria to flourish and release toxins that attack the lining of the intestines. Many patients require repeated courses of antibiotics to kill the C. diff.
Over the past 20 years, physicians have experimented with what they euphemistically call "fecal transplants" to treat C. diff. These involve taking stool from a patient's family member, mixing it with water and injecting it into the patient's bowel using an enema.
The researchers used feces from family members because they are likely to have the closest match to what the patient's formerly healthy intestinal bacteria community was. The feces was processed until it contained only bacteria, no fecal matter. Patients are tested for blood-borne diseases and other pathogens.
The bacteria is placed in gelatin capsules, which take 60 to 90 minutes to dissolve. Patients typically take 24 to 34 capsules, depending on their body weight. These dissolve in the lower bowel, Louie said.
"One of my patients was a 6-year-old boy who had a heart transplant," Louie said. The antibiotics necessary for the transplant had caused recurring C. diff infections. "The patient came in and had 12 pills in about three minutes, and that was the end of a C. diff for him."
The intestines are "a very complex, interdependent ecosystem that performs many tasks that are only now beginning to be understood," said Tomas Moore, a professor of medicine at the University of Kansas-Wichita. He has been doing fecal transplants on patients since the late 1990s.
The Food and Drug Administration formerly required physicians doing fecal transplants to get approval for the procedure as a drug trial. "They have since relented and now allow individual physicians to use the treatment, only for relapsing C. diff infections. Anything else requires a formal application," Moore said.
There have been more than 700 cases of fecal transplants that doctors have documented, and all have found it to be safe, Moore said.
Pharmaceutical companies are working on finding out what bacteria are important in restoring healthy intestinal bacteria. These could then be grown in a laboratory and manufactured, Louie said.
That seems overkill, Moore said. "Just speaking for myself, it would be difficult to compete against the ready availability and very cheap acquisition costs of human poop."