Debilitating bowel pain is common, but the underlying cause is still unclear. Usually it is an intestinal infection that triggers immune responses. These can result in everyday foods being classified as harmful and causing severe and persistent pain.
A new study published in the journal Nature reports in mice and humans that a novel mechanism contributes to chronic bowel pain.
Chronic bowel pain
Pain occurs to alert the body and protect it from actual or potential tissue damage. There are three common forms of pain – nociceptive pain, which is caused by damage to body tissues. Inflammatory pain, normal inflammation caused by an inappropriate response by the body’s immune system, and chronic pain, defined as pain that lasts for at least 12 weeks.
One of the most common causes of chronic bowel pain is irritable bowel syndrome (IBS), which causes cramps, diarrhea, and constipation. The chronic pain in this condition is often attributed to allergies, but there is no precise cause or mechanism for it.
Often times, the pain associated with IBS cannot be easily localized and it is difficult to determine the cause or origin of the pain. Usually, people with pain in their internal organs have the problem of not knowing the root cause. For example, IBS, a disease that affects about 11 percent of the world’s population, has no specific disease characteristics that distinguish one disease from another.
IBS can be triggered by risk factors like imbalance in the intestinal flora and gastroenteritis due to ingestion of contaminated food or water, stress, and changes in intestinal-brain communication.
The study’s researchers also found that bacterial infection can alter the immune response in the gut, causing some foods to be perceived as harmful. As a result, the body attacks the food and surrounding tissues, causing persistent bowel pain.
In the study, researchers at the Laboratory for Intestinal Neuroimmune Interactions, the Translational Research Center for Gastrointestinal Disorders, the Department of Chronic Diseases, Metabolism and Aging at KU Leuven in Belgium explain the new mechanism by which an intestinal infection changes the organ’s tolerance of antigens . that can be found in many foods.
The intestinal immune system recognizes these antigens as harmful. As a result, people with IBS feel pain when they consume food. They also showed that bacterial infections and bacterial toxins can trigger an immune response that triggers the production of dietary antigen-specific immunoglobulin E (IgE) antibodies in mice.
Visceral pain occurred after ingestion of the food antigen. The pain signal came from the histamine-H1-mediated sensitization of visceral afferents. In addition, the injection of food antigens, including wheat, soy, milk, and gluten, into the lining of patients with IBS triggered local edema and mast cell activation, which are hallmarks of inflammation.
After the infection, the team also found that the egg white protein stimulated a chain reaction, similar to a food allergy. The antigen bound to the antibodies IgE associated with mast cells.
“Our results identify and characterize a peripheral mechanism underlying foodborne abdominal pain, creating new opportunities for treating irritable bowel syndrome and related abdominal pain,” the researchers concluded in the study.
Along with their results, the researchers suggested various treatment options. First, they recommended improving the intestinal barrier function to reduce the access of the intestine to the intestinal immune system. Second, they suggested targeting IgE antibodies that could cause inflammation and are specific to the food of interest and target the molecules released by the mast cells. Finally, they recommended blocking the colon’s sensory nerves that transmit information to the brain to cause pain.
The team said more research is needed to develop therapeutics that will help people with IBS.