to test this theory, researchers infected mice with a stomach bug at the same time they gave them ovalbumin, the main protein found in egg whites. once the mice recovered from the infection, they gave them ovalbumin again and found it provoked a similar response from the immune system, causing mast cells to release histamine that prompted intolerance and pain in the digestive system. they also noted this immune response only occurred in the specific area of the intestines that was subject to the infection, suggesting there exists a range of food-related immune diseases.
“at one end of the spectrum, the immune response to a food antigen is very local, as in ibs,” boeckxstaens said. “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.”
the researchers then tested their findings on humans by injecting antigens connected to ibs, such as wheat, gluten, soy and cow milk, into the intestine walls of a dozen patients with the disease. it produced the same localized immune reaction seen in mice — a reaction that did not occur in participants without ibs. “this is further proof that the mechanism we have unravelled has clinical relevance,” boeckxstaens said.
because of the small sample size used in this research, a larger study using anti-histamines to combat ibs is already underway to confirm its findings. “but knowing the mechanism that leads to mast cell activation is crucial and will lead to novel therapies for these patients,” 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.”