Dr. Elaine O. Petrof, MD, MSc, FRCPC

Clinician-Scientist, Kingston General Hospital Research Institute; Associate Professor, Department of Medicine, Queen’s University
Researcher of the month: 
Jun 2016

Following her gut

Medical treatment can sometimes be every bit as unpleasant as the disease it is meant to cure, but infectious disease specialist Elaine Petrof would argue that faecal transplants stand in a class by themselves.

“I can’t lie,” she says, recalling how she nearly threw up when she first conducted this procedure almost a decade ago. “It is kind of gross when you think about what it involves.”

And highly effective, she hastens to add. Dr. Petrof has been able to rid patients of the notorious Clostridium difficile (C. diff) bacterium, which spread rapidly in Canadian hospitals in the early 2000s. The infection sets up shop in the intestinal tract, causing pain and diarrhea as well as systemic breakdowns that can be fatal.

These effects can be altogether stopped, however, by introducing bacteria from a healthy donor’s faeces into the patient’s gut through a colonoscope or by enema. As crude as this strategy sounds, its success testifies to how much we have to learn from the microbiome, the massive and diverse colony of bacteria each of us carry around in our bodies.

Dr. Petrof became fascinated by the health implications of this biochemical frontier after completing her medical residency and study of gastrointestinal infectious disease in the United States. C. diff was still on the on the rise in 2008 as she arrived at Kingston General Hospital, where she realized it was possible to resolve this infection with faecal transplants.

“That’s what got me interested in developing synthetic stool, which is like a super probiotic, a community or an ecosystem of bacteria,” she says. “It’s like a cleaned-up stool transplant.”

Ever mindful of the way such work is perceived by the public, Dr. Petrof and her colleagues refer to it as “Repoopulate”. That name conveys the underlying principle, which is that “good” bacteria from a donor’s faeces can colonize a recipient’s bowels and eventually crowd out “bad” bacteria that represent an infection. However, moving beyond the simple transfer of bacteria en masse to a more targeted method has posed a significant research challenge.

“Part of the reason that people haven’t used this approach of developing communities of gut bacteria is that they’re actually quite tricky to grow,” she explains. “You need highly specialized equipment to do that.”

Thanks to a grant from the Canada Foundation for Innovation, Dr. Petrof is building just such equipment. Her laboratory is already home to a continuous culture chemostat known as a “robo-gut”, which nurtures bacterial colonies and mimics the intricate conditions within the human digestive system. Now she is assembling a facility that will turn out specific mixtures of these agents in quantities sufficient to deliver to patients on a routine basis. Ultimately she would like to demonstrate the value of such a treatment in a formal clinical trial.

That ambition has added significantly to the paperwork crossing her desk, since Health Canada regards these mixtures as subject to the same regulatory regime as any pharmaceutical agent. Fewer of these restrictions apply to a straightforward faecal transplant, which is akin to remedies using unadulterated, natural products.

Undaunted, Dr. Petrof remains eager to refine this technique in order to tackle problems such as chronic obesity, Crohn’s Disease or ulcerative colitis, which may be driven by distinct populations of bacteria that are naturally present within a patient.

“Since you can’t change people’s genetics, you actually can potentially manipulate their microbiomes, which may be another way to come at the disease,” she says. “There may be diseases where there’s an imbalance of bacteria and you just need to patch up the ecosystem. There may be others where you have knock certain bad bacteria out and replace them.”

She adds that it is early days for this kind of research, which makes the task ahead all the more exciting.

“I see where we are now with microbiome therapy as being where biologics and antibodies were in the 1970s,” she says, pointing to the research that led up to new products such as the drug infliximab, which ushered in a new avenue for dealing with autoimmune disorders. In the meantime, while Dr. Petrof remains no fonder of handling faeces than she was the first time she transplanted it into a patient, she is more than eager to seek out the surprises it contains.

“There’s not very many fields where you’re doing research that you can truly say you’re discovering new life forms, new bacteria that have never been described before,” she concludes.