Scientists have discovered that psychological stress can induce immune responses to foods that can cause symptoms when food is consumed again, the results that demonstrate the potential role of stress in the symptoms of irritable colon syndrome (IBS), according to a recent study published in Gastroenterology.
“This study highlights the key role that activation of the immune system by food plays in many diseases beyond those that we generally consider food allergies,” said Cecilia Berin, PHD, professor of research on food allergies and co-author of the study. “This study really shows the molecular explanation of the reasons why food can be a trigger not only for a food allergy, but also pain during irritable colon syndrome.”
Previous work has shown that bacterial infection in mouse models can cause the development of immune responses and allergic food reactions that cause abdominal pain induced by food, the symptom of irritable colon syndrome. We also know that IBS can develop after an infection, but this only explains that a small part of IBS cases, according to Berin.
In this study, scientists aimed to determine if similar immune responses caused by psychological stress could contribute to the signaling of the pain induced by food.
“Psychological stress can have direct effects on the physiology of the gastrointestinal tract,” said Berin, who is also a professor of medicine in the allergies and immunology division.
First, the researchers exhibited ovalbumin mice, a protein found in egg whites, during a stressful test called water avoidance stress. A
Scientists then measured the visceromotive responses (contractions of the abdominal muscle) and the nervous recordings to intestinal distension (excessive intestines) to determine the nociception of the mouse, or the response of the nervous system to harmful stimuli. Responses to IgE antibodies and type 2 immunity, which is triggered by allergic reactions, were measured using pharmacological and genetic approaches.
In mice exposed to ovalbumin during the stress test, scientists found that re -exposure to ovalbumin increased pain signaling in mouse and small intestine colon. These responses to pain also depended on mastocytes (specialized white blood cells), local IgE antibodies and stat6 signaling, which plays a role in cell proliferation.
When these mice have been treated with pyrilamin, a drug currently used to treat allergic symptoms, researchers found that the drug inhibited an increase in the activity of sensory neurons and also reduced nervous shooting, causing intestinal distension.
According to Berin, the results were particularly surprising in that allergic reactions could change the normal function of the gastrointestinal tract and cause pain without causing systemic allergic reactions such as anaphylaxis.
“The fact that the IgE antibodies that we know trigger allergic reactions were at the heart of these symptoms which were quite distinct from what we see in the food allergy that I found really interesting, the idea that these immune responses could be so localized and always functional,” said Berin.
In the future, Berin said that the next steps include the study of gastrointestinal immune cells for SCI patients to determine whether food-based immune responses are also observed in patients.
“The targeting of the same ways that are involved in food allergy have effectively reduced pain signaling in mice. We have a number of tools that target these factors that can be used in humans, which is potentially highlighted a new way of treating irritable colon syndrome, “said Berin.
This work was supported by the subsidy of the Institute Translational Institute of the Queen (time).