IBS

THE AIM IS TO GIVE THOSE SUFFERING FROM IBS BETTER TREATMENT

Irritable bowel syndrome (IBS) is a gastrointestinal disorder that plagues nearly a tenth of the population in the western world. Although it does not shorten life, it has a major impact on people’s lives and health. Magnus Simrén wants to take a holistic approach and develop better treatment.

Irritable bowel syndrome (IBS) is estimated to affect around one in ten people in the western world. Magnus Simrén, a researcher at the University of Gothenburg and doctor at Sahlgrenska University Hospital, found himself devoting his medical career to gastroenterology from early on.

“In this area IBS is a fascinating condition, because the interaction between the brain and the gut is a key aspect of the symptoms,” he says.

Although IBS is common, it has been unclear why the condition arises.

“We now believe that it is partly to do with what happens in the microbiome in the gut – an interaction between food, gut bacteria and the immune system,” says Magnus Simrén.

In one in five people who get IBS, the condition arises after a gastrointestinal infection.

“Patients might say ‘I had a stomach upset in Thailand and I’ve had stomach problems ever since’,” he says.

In February this year a scientific study was published in Nature in which Belgian researchers describe a possible mechanism. In tests involving mice they introduced a gastrointestinal infection and at the same time gave the mice a certain type of food. After the mice had recovered from the infection, they were given the same food again and experienced something that resembled an allergic reaction along with pain sensitivity in the gut.

“The interpretation is that the immune system is activated incorrectly when the infection takes place. Normally immune cells in the gut do not react to food, which is called oral tolerance. When they do, you get an overreaction to the foods,” says Magnus Simrén. Last year his team was able to show that 30 percent of patients with IBS were infected with a specific bacterium called Brachyspira. In contrast, this bacterium was not found in people without IBS, as they published in Gut.

“Patients also had an allergy-like activation of the gut’s immune system. Whether that is a reaction to the bacterium itself or to food, for example, is still uncertain and is something that needs to be studied further,” he says.

They will now do this in the project Irritable bowel syndrome (IBS): A disorder caused by microbes, leading to loss of tolerance to dietary antigens? One part of this involves using allergy tests in the gut to investigate which foods infected individuals are sensitive to.

“We’ll be using a technique similar to the prick test done on the skin for allergy testing. The difference is that we’ll be doing the test in the gut and testing locally there for substances such as soy, egg, gluten and other foods,” he says.

They will also continue to map the Brachyspirainfected patients – for example as regards their symptom profile, other gut flora composition and function, and the functioning of the immune cells in the gut. In the third part of the project the researchers will attempt to restore the patients’ gut function in various trials.

“Here we want to try out many different approaches. Is excluding certain foods effective? Can the Brachyspira infection be eradicated using bespoke antibiotic treatment? Or how about if we use certain drugs to block nerve function in the gut?”

For this ambitious project to achieve its objective,

Research is teamwork: Magnus Simrén with colleagues Piyush Patel and Annika Lundqvist.

When researchers examined samples from patients with IBS and healthy individuals they found a specific bacterium in the gut of IBS patients. Now the infected patients will be studied further.

the financial support from the Erling-Persson Foundation is highly significant, says Magnus Simrén – emphasising that it also sends an important signal. “It’s great to see a large donor devoting resources to a condition that has not traditionally been considered worthy of attention, which may be due to the fact that it’s not life-threatening and also that it’s mainly women that are affected. I’m pleased the Foundation is venturing to fund research into IBS, which has such a great effect on so many people’s lives over a long period – often throughout their lives, from its onset at a young age right through to the autumn of their years,” says Magnus Simrén.

20%

A diagnosis of irritable bowel syndrome (IBS) is made for chronic complaints involving stomach pain combined with variation in bowel habits. Investigations suggest it is prevalent in around 20% of people.

2 in 3

Between 5 and 10 percent of the population are estimated to meet the diagnostic criteria for IBS. Two thirds of those affected are women and the onset of IBS usually occurs between the ages of 20 and 40, but many already suffer from it as children.

15–20%

For 15–20 percent of patients the condition comes on after a stomach infection. There is no cure, but there are various things that can be done to alleviate the symptoms.

ABOUT THE PROJECT Project Manager: Magnus Simrén, Professor of Medical Gastroenterology at the University of Gothenburg’s Institute of Medicine and Senior Consultant at the Institute of Medicine, Department of Medical Gastroenterology and Hepatology at Sahlgrenska University Hospital in Gothenburg.

Title: ‘Irritable bowel syndrome (IBS): A disorder caused by microbes, leading to loss of tolerance to dietary antigens?’

What it involves: Researchers found the bacterium Brachyspira present in the gut in one in three IBS patients, but not in healthy individuals. They want to investigate in various ways whether this bacterium activates the gut’s immune system, making the gut sensitive to foods, and to test out various kinds of treatment.

Funding: The Erling-Persson Foundation is supporting the project with SEK 3 million per year for three years, totalling SEK 9 million.

Read more: Nature 2021: https://pubmed.ncbi.nlm.nih.gov/33442055/ Gut 2020: https://pubmed.ncbi.nlm.nih.gov/33177165/