The capsules — custom-made for each patient — are packed with microbes harvested from fresh, human feces.
After about 90 minutes in transit, the pills release their living cargo into a patient’s intestine, where the microbes start to multiple and restore the gut ecosystem.
“It’s totally un-invasive,” says Louie, an infectious diseases expert at Calgary’s Peter Lougheed Hospital, who invented the capsules to treat stubborn infections caused by C. difficile, a bacterium that can trigger relentless and life-threatening diarrhea.
Louie, who teaches in the University of Calgary’s medical school, will report at an international conference in San Francisco Thursday on how the capsules are proving a “convenient and effective” way to stop recurrent C. difficile.
Gerri Hamby can attest to that. The 66-year-old Alberta businesswoman recently swallowed 35 of the capsules in Louie’s lab.
Dr. Tom Louie, faculty of medicine at the University of Calgary, with his patient Gerri Hamby as she consumes a fecal transplant in form of a capsule. ~ Postmedia News Photo
The pills — filled with “good bacteria” from feces donated by her daughter — appear to have put an end to a C. difficile infection that had made Hamby’s life miserable for months. “I’m thrilled to be back on track,” says Hamby.
Louie’s pills add a refined touch to the world of fecal transplants, which are typically done by enema or using a colonoscope. “They’re probably a lot more palatable to people, no pun intended,” says Dr. Susy Hota, an infectious diseases specialist at Toronto’s University Health Network, who is also doing experimental transplants.
A fecal transplant is exactly what it sounds like. Feces — or in Louie’s pills, fecal microbes — from a healthy person are transferred to the colon of people infected with C. difficile.
Despite the yuck factor, a growing number of doctors support the transplants, which studies indicate are remarkably effective. A European study, published earlier this year in the New England Journal of Medicine, found fecal transplants cured 15 of 16 people with recurring C. difficile, compared to a less than 30-per-cent cure rate for drug therapy.
Canadian health administrators, who have until recently shunned fecal transplants as unproven and risky, are now allowing trials in several hospitals.
A study involving 156 patients is underway at McMaster University in Hamilton and expanding to include patients in Vancouver, Edmonton and Kingston. Hota’s team in Toronto has a trial to compare fecal transplants with drug therapy in 140 patients. Researchers in Guelph and Kingston, Ont., are planning to scale up use of an artificial fecal mixture called “RePOOPulate.” And Louie, who has given capsules to almost 40 patients so far, is working with a research institute in Britain to identify the fecal microbes he’s packing into his pills.
In an interview, Louie estimated that about 30,000 Canadians a year are infected with C. difficile, a weedy microbe that can infect people’s guts after they take antibiotics. Antibiotics kill or slow the growth of bad bacteria, but they also kill off good bacteria. Hundreds of Canadians die each year after becoming infected with C. difficile — most of them elderly individuals who pick up strains in hospital that have grown resistant to common treatment.
‘I think it’s very unlikely this is not going to become standard of care.’
Many more — Louie estimates about 2,700 Canadians a year — end up with recurrent C. difficile infections, which they cannot shake.
“It’s horrible,” says Hamby, who was hospitalized for five days in June for dehydration and has stuck close to home ever since because of the diarrhea. “When you have C. diff and you have to go, you go; it’s very sudden,” says Hamby, an avid golfer who didn’t venture onto the course this summer.
Louie says he now offers fecal transplants as a last resort for people who can’t be cured of C. difficile with drugs. But it could be just a matter of time before transplanting fecal material become routine.
“The anecdotal evidence is so powerful that I think it is very unlikely this is not going to become standard of care,” says Dr. Ted Steiner, an infectious diseases physician at Vancouver General Hospital.
Steiner was recently given the green light to begin enrolling patients as part of McMaster’s multi-centre trial comparing the effectiveness of transplants made using fresh feces with transplants made from frozen feces that could be stored in stool banks.
Using frozen stool from donors, who have been pre-screened to try to ensure they won’t pass on pathogens, would make it logistically easier to offer transplants, says Dr. Christine Lee, at St. Joseph’s Healthcare in Hamilton, who heads the McMaster trial.
For patients who can’t shake C. difficile infections — or can’t afford costly drugs that can keep the microbe in check — Lee says fecal transplants appear to be a simple, inexpensive and “highly efficacious” treatment.
She says provincial drug plans tend to provide only limited coverage for the medications that people with recurrent C. difficile often need to take indefinitely.
The doctors say fecal transplants restore peace in the gut ecosystem within days. “They pretty much work 19 times out of 20,” says Louie.
But the procedure is not without risks. As many as 1,000 different species of bacteria, fungi and viruses live in the human gut. And most of the organisms have not been identified, making it impossible to know just what is being transplanted.
“We have no idea what the long-term impacts of fecal transplants will be,” says Emma Allen-Vercoe, at the University of Guelph, who is working to isolate and identify fecal microbes. She’d like to see a registry set up to keep track of transplant recipients.
Louie started doing fecal transplants in people’s homes in 1996 to avoid trouble with hospital administrators in Calgary. He says he has treated about 115 patients. Just over 70 people received diluted feces by enema, and about 40 have swallowed the capsules.
Louis says he came up with the idea for the pills in 2010 when two of his female patients could not tolerate enema transplants.
For the pills, he says the preferred donor is a family member who has been screened for pathogens. A fresh stool is mixed into a solution and spun around in a centrifuge to separate the microbes.
The “pure bug prep” is encapsulated in gelatin to ensure the pills make it past the harsh environment in the stomach and into the small intestine before dissolving and releasing their contents, says Louie: “The transit time to the small intestine is one to two hours.”
It may eventually be possible to pack key microbes into just a few pills, but Louie’s patients now have to swallow 25 to 35 of the capsules on an empty stomach.
Hamby says the large white pills are tasteless and go down easily with a bit of water. As for the pills’ contents, “I just put that out of my mind,” Hamby says with a laugh.
Louie says making the pills is labour-intensive and “a money-losing proposition.”
Still, the doctors foresee the day when capsules loaded with key fecal microbes might be routinely given to restore the gut ecosystem not only when people become infected with C. difficile but whenever someone takes an antibiotic. “We might be able to dramatically reduce the incidence of C. difficile,” says Steiner, as the diarrhea-causing bacteria would no longer have a chance to take over.
– Research for this story was funded in part by a journalism award from the Canadian Institutes of Health Research.