Gut Feelings: Canada has one of the highest rates of IBD in the world. Why?

Living with inflammatory bowel disease (IBD) can be many things, but to be blunt, it’s literally and figuratively shitty.

IBD is a class of chronic illnesses where the immune system attacks the digestive tract and causes inflammation. The main forms of IBD are Crohn’s Disease and Ulcerative Colitis. Symptoms can include extreme fatigue, weight loss, diarrhea and abdominal pain (Dan O’Bannon’s painful experiences with Crohn’s Disease famously inspired the Chestburster scene from Alien).

One in 140 Canadians are living with IBD — among the highest incidences of this disease class in the world. Most people are diagnosed before age 30.

There are an estimated 322,600 Canadians living with IBD and this number is projected to increase to 470,000 or 1.1 per cent of the population by 2035, according to the the Impact of by Crohn’s & Colitis Canada.

According to clinical assistant professor and head of the Vancouver Island IBD Clinic Dr. Dustin Loomes, westernization and industrialization are key factors to consider when looking at IBD in Canada.

“The move to sanitation, running water, antibiotic use and then westernization of our diet has all led to changes in our exposure to native pathogens being decreased,” said Loomes.

IBD stems from a disordered relationship between the immune system and the gut. IBD risk is a complex interplay between genetics and environmental factors like diet, upbringing, smoking and more.

Food for thought

The western diet has been described in literature as “the most ubiquitous environmental factor in [IBD],” with meta-analyses and reviews supporting diet as a major risk factor. The western diet is known for its high sugar, fat and refined grain content, with limited vegetable and fruit intake. It has a greater emphasis on animal proteins and fats, and food additives.

Countries known for following a western diet tend to have higher incidences of IBD and nations newly adopting a western diet and lifestyle appear to be seeing a rise in cases of IBD.

According to Loomes, this “derangement of what we're eating” stems partially from chemicals an antibiotics added to the food supply, along with an overemphasis on processed and ultra-processed foods. Experts have also pointed to sugary food additives like saccharin and sucralose as concerning.

“[These changes are] rampant and really just straying away from what we would have eaten evolutionarily,” Loomes said.

Limited fibre and increased meat intake characteristic to the western diet have been theorized to be problematic for IBD onset, but this is complex. For example, one study observed that a high fibre diet decreased the risk of Crohn’s Disease but not Ulcerative Colitis.

According to Dr. Genelle Lunken, assistant professor in pediatrics and registered dietitian, fibre’s relevance to IBD development likely stems from how it interacts with our gut microbiome.

Fibre is a component of plant-derived foods that cannot be broken down by our body’s enzymes. Since it doesn’t get digested in the stomach, it carries on its merry way to the colon, where most of our gut bacteria lives.

Lunken explained fibre tends to be used as a fermentable energy source by “more beneficial microbes.” And these fibre-munching bacteria tend to increase production of short chain fatty acids — anti-inflammatory metabolites that support the integrity of gut lining, mitigating dysregulated interactions between the gut and the external environment.

However, the benefits of fibre for people with IBD depends on the type of fibre, their specific gut microbes and whether the patient is in an active disease state. According to Lunken, the diet-IBD connection is understudied, with literature relying heavily on correlative studies.

Wild, sterile west

The hygiene hypothesis is a major modern development in our understanding of how the immune system is shaped. It is based on an observed trade-off in Western countries: a decrease in infections in early life and an increase in autoimmune disorders and allergies.

According to Loomes, more sterile environments have limited our exposure to viruses, bacteria and parasites that we would have encountered evolutionarily.

“So, [the gut] immune system — which is a fairly large immune system — is sitting idle for decades. In people who have a genetic predisposition to autoimmunity, it takes some of the conditions that are ripe for that, for autoimmunity to be triggered,” said Loomes.

Children who grew up in less sterile spaces have a lower IBD incidence. IBD risk appears to be halved for kids who grew up around livestock, according to a Danish study. The family dog may also be your gut’s best friend as pets also appear to protect against IBD development. The hygiene hypothesis is not a condemnation of cleanliness, but rather an acknowledgement of the importance of early life exposure to microbes in shaping our immunity.

Growing up in a sterile environment may even be detrimental for how your immune system interacts with normal gut flora, according to Lunken.

“The immune system just hasn't been exposed to enough microbes and as soon as something new comes along, whether it's pathogenic or not, it might recognize that as foreign.” She suggested this may lead to chronic inflammation that could develop into immune-mediated conditions like IBD.

Areas with the highest IBD prevalence tend to be Northern countries with higher levels of industrialization, but also lower levels of sun exposure.

Vitamin D — a potent modulator of the immune system — might also impact the immune systems of the Great White North. Studies have observed that people in more Northern latitudes like Scandinavia and Canada which receive less sunlight have a greater risk of IBD, specifically Crohn's Disease.

Loomes highlighted that it’s not yet possible to prove whether diet, vitamin D exposure, lifestyle or other factors are responsible for where IBD tends to concentrate.

Genetics play a big role in IBD too. People are more likely to be diagnosed with IBD if they have a relative with the disease. Genetics and environmental elements work together to make certain people more at-risk for developing IBD.

According to Loomes, a major misconception about IBD is that there “is no known cause.”

“We don't know for an individual patient ... the exact factors for them that cause IBD but we in general know what causes [it],” he said. He pointed to regions of the world, like Eastern Asia and Africa, that are seeing an increase in IBD incidence after adopting a Western diet, stringent sanitation measures that limit microbial exposure, antibiotic use and a more processed food supply.

“I think overall that does provide reassurance to patients that it's not this giant mystery.”

Supporting a growing community

With 1.1 per cent of the Canadian population predicted to be diagnosed with IBD by 2035, institutions need to start thinking about how to better serve this growing community. Though the incidence or rate of new diagnoses has relatively stabilized, the prevalence or overall number of cases is growing.

As a physician who supports IBD patients on the regular, Loomes emphasized the need for more multidisciplinary care.

“I firmly believe that a clinic model that incorporates dietitians, psychologists, nursing and clinicians is a much more holistic method to provide care for a chronic condition that can have far reaching effects in terms … physical health as well as mental health,” he said. Loomes said a care team model could also cut costs, since not all IBD patients need to see a specialist at every visit.

And boy does IBD cost. In 2023, IBD was estimated to cost $5.4 billion dollars in Canada, with $3.3 billion coming from public health care systems and the rest being indirect and out-of-pocket costs.

Most of these costs stem from biologics — a class of immune-suppressing medications essential for maintaining remission in IBD patients. Annual costs for biologic therapies like Humira and Entyvio sit around $20,000 per year (they’re covered by insurance in BC, don’t worry).

The IBD Centre of BC and the Vancouver Island IBD Clinic are excellent resources working to improve quality of life for the IBD community.

The IBD Centre of BC is a “multidisciplinary clinic, education and research centre,” according to its website. Lunken — a dietitian and scientist at the Centre — is interested in how the diet, nutrition and the gut microbiome drives disease. She said researchers at the Centre are working hard to find biomarkers in IBD that would signal to clinicians the severity and characteristics of someone’s disease. This can streamline treatment plans and predict which medication is best for patients.

The Vancouver Island IBD Clinic is a public health foundation that aims to advance the quality of care for people with IBD in BC and across Canada. Loomes said the Vancouver Island IBD Clinic has several ongoing works, including a national project that uses tech to drive quality of care at individual patient level.

Modernizing IT infrastructure to be more comprehensive can help better support patients by streamlining communications between health care workers, said Loomes.

Updating technology, research and facilitating a care team model are all important ways to make a future for people living with IBD.

“It's challenging but it's much more challenging to live with the conditions, so it's only right that we try and do everything we can to make sure that all patients have access to good quality care,” said Loomes.

Living with IBD isn’t just about learning to cope with symptoms, manage a treatment plan or fend off family member’s fad diets. It’s sifting through an immense amount of literature, data and medical advice. Gut Feelings is a column to highlight the stories of IBD warriors and researchers, while bringing a bit of flair to IBD education.