Scientists say they believe they have discovered the mechanism behind what causes irritable bowel syndrome (IBS).
In a new study, researchers discovered that stomach infections such as food poisoning that trigger cells that release a compound called histamine.
Histamine, in turn, can lead to an ‘allergy’ that causes digestive intolerance and increases abdominal pain.
The team, from Katholieke Universiteit Leuven, in Belgium, says the findings suggest that treating IBS patients with common allergy medications called antihistamines may be able to relieve their symptoms.
A new study from Katholieke Universiteit Leuven, in Belgium, found that IBS can be triggered like an ‘allergy,’ releasing a compound called histamine that causes abdominal pain (file image)
IBS is an intestinal disorder that causes abdominal pain, bloating, cramping, and diarrhea or constipation.
It affects between 10 and 15 percent of the US adult population, but only around five to seven percent have been diagnosed, according to the American College of Gastroenterology.
Treatments currently consist of managing symptoms such as avoiding any trigger foods, drinking plenty of fluids, exercising regularly and getting enough sleep.
‘Very often these patients are not taken seriously by physicians, and the lack of an allergic response is used as an argument that this is all in the mind, and that they don’t have a problem with their gut physiology,’ said lead author Professor Guy Boeckxstaens, a gastroenterologist at KU Leuven.
‘With these new insights, we provide further evidence that we are dealing with a real disease.’
Previous research conducted by the team revealed that certain foods activate a type of cell called a mast cell that releases histamine, a compound that regulates physiological function in the gut.
Because many people report IBS after suffering a gastrointestinal infection, for the study, published in the journal Nature, researchers infected mice with a stomach virus and then split them into two groups.
One group was fed ovalbumin, a protein found in egg white that provokes an immune response, and the other group was not.
After the bug cleared, the ovalbumin group was fed the protein a second time.
Results showed that the mice has their mast cells activated, which increased histamine release and led to digestive intolerance and increased abdominal pain, almost as if they had an allergy.
After examining the mice to determine what connected the ingestion of ovalbumin to activation of the mast cells, they discovered it only occurred in the part of the intestines that had been infected by the stomach virus.
‘At one end of the spectrum, the immune response to a food antigen is very local, as in IBS,’ said Professor Boeckxstaens.
‘At the other end of the spectrum is food allergy, comprising a generalized condition of severe mast cell activation, with an impact on breathing, blood pressure, and so on.’
Next, they tested to see if the immune response would be localized in 12 IBS patients and 12 health volunteers.
When foods associated with IBS, such as gluten, wheat and soy, were injected into the intestinal walls of the IBS patients, they had the same reactions as the mice did.
The team plans to test a larger amount of patients in a clinical trial and says the findings could result in IBS patients being treated with allergy medications known as antihistamines.
‘Knowing the mechanism that leads to mast cell activation is crucial, and will lead to novel therapies for these patients,’ Professor Boeckxstaens said.
‘Mast cells release many more compounds and mediators than just histamine, so if you can block the activation of these cells, I believe you will have a much more efficient therapy.’
