The Good Bugs and the Bad Bugs

New U of G researcher studies gut microbes to help develop therapies for inflammatory bowel disease


Prof. Emma Allen-Vercoe’s science complex lab has been developed to study fastidious bacterial species from the gut and is one of the few places in Canada where this research can be done.
Prof. Emma Allen-Vercoe's science complex lab has been developed to study fastidious bacterial species from the gut and is one of the few places in Canada where this research can be done. Photo by Martin Schwalbe

Did you know that right now you have more bacteria living in your gut than there are people living on the planet? Not necessarily a topic to discuss around the dinner table, but it's true, says Prof. Emma Allen-Vercoe, who joined the Department of Molecular and Cellular Biology in December after spending six years at the University of Calgary - four as a post-doctoral researcher and two as a faculty member.

The bacteria or “bugs” that live in the gut are the focus of Allen-Vercoe's research.

“It's becoming increasingly clear that our gut microflora are key to our overall health, yet very little is known of the ecology and physiology of these organisms and their interactions with host cells,” she says.

All humans have unique microflora or a “poo print” made up of up to 1,000 different bacterial species that remain with them throughout their entire life.

“The microflora contribute a great deal to health,” she says. “Research suggests they play a huge role in obesity and cancer, and the list goes on.”

Allen-Vercoe, who completed a B.Sc. at the University of London and a PhD at the Open University in Milton Keynes, England, in collaboration with the Centre for Applied and Microbiological Research, is currently studying how the gut microflora contribute to inflammatory bowel disease (IBD), an umbrella term for ulcerative colitis and Crohn's disease.

With ulcerated colitis, patients have an inflamed colon, whereas Crohn's patients can have inflammation anywhere from the mouth to the anus, she says. Symptoms of these diseases include diarrhea, weight loss and abdominal pain, and although therapies are available to lessen these symptoms, IBD can be fatal in severe cases, and there is no cure.

“We do know, however, that the bacteria that live in the gut play a huge role in triggering and exacerbating these diseases. Patients with IBD may have a slightly lower diversity of bacterial flora than healthy people do, and we don't know why. We want to figure out which bacterial species are the ringleaders, so to speak, in triggering IBD. If we can find this out, it will allow us to develop new therapies for this debilitating condition.”

Although antibiotic therapies are helpful, no antibiotic targets one specific bacterium, says Allen-Vercoe.

“The problem is, there are beneficial bacteria that live in the gut as well as harmful species, and antibiotic therapy could wipe out the good bacteria, causing more harm to the patient. Thus, an important aim of my research is to figure out which are the bad bugs in IBD.”

She's been studying these bugs since 2005 and is especially interested in Fusobacterium nucleatum, an invasive anaerobic bacterium that commonly lives in the mouth and causes an inflammatory disease called periodontitis. She's trying to learn more about how it interacts with the cells inside the gut.

“It seems to be a very complicated area I've landed myself in,” says Allen-Vercoe, who has examined biopsy samples from IBD patients and has already found F. nucleatum to be an exacerbating factor in the condition. Despite this conclusion, the cause of IBD is still unknown and the search continues, she says.

Research of this kind has been difficult to do in the past because most of the bacteria that live in the gut are nutritionally fastidious and grow only in conditions without oxygen, she says.

“It's tricky to create appropriate conditions available to house so many of them and grow them outside their natural habitat inside the human body.”

Allen-Vercoe's lab in the science complex, which was set up while she was still at Calgary, has been developed to study fastidious bacterial species from the gut. It's one of the few places in Canada where this research can be done.

The lab has already garnered attention from scientists at the Broad Institute of MIT and Harvard University who are working with the National Institutes of Health on a multi-million-dollar Roadmap Initiative that aims to sequence genomes of bacteria isolates from humans in an attempt to complement the now complete human genome sequence.

The lab has a collection of about 1,000 different bacterial isolates, some of which have not previously been discovered and are currently being categorized. Allen-Vercoe is supplying Broad with isolates that account for 20 per cent of what the institute needs to complete the first phase of the project.

“What was surprising to us was that we've found so many novel species just by using specially adapted microbiological techniques,” she says.

Allen-Vercoe, who moved from Calgary in October with her husband and their children, Phoebe, 8, and Zoe, 18 months, says the decision to relocate to Guelph was an easy one to make because of the University's reputation.

“The microbiology program is highly respected across Canada. In fact, the best graduate students we had at Calgary did their undergraduate degree here at Guelph. My former colleagues are envious that I'm getting to work with these students before they'll have the chance to.”