For millions of people, food isn’t just about nourishment, it’s a potential danger. Food allergies affect roughly 1 in 10 adults and 1 in 13 children in the U.S., and the most common culprits include peanuts, tree nuts, milk, eggs, shellfish, soy and wheat. While many reactions are mild, some can escalate into anaphylaxis, a life-threatening emergency that can cause breathing problems, a sudden drop in blood pressure and even death.
Scientists have long known that the immune system plays a central role in food allergies, but why one person experiences mild hives while another needs emergency treatment has been a mystery. Now, two new studies published in Science suggest the difference may come down to how the gut responds when it detects certain allergens.
In experiments with mice, researchers discovered that severe food-allergic reactions were linked to higher levels of inflammatory molecules called leukotrienes, made by immune cells in the lining of the small intestine. These molecules seemed to act like “gate openers,” making it easier for allergens to cross from the gut into the body and set off a dangerous chain reaction.
Some mice naturally had a better defense system, a more active form of an enzyme that breaks down one of these molecules before it can cause trouble. Others lacked this advantage, making them more vulnerable.
The studies also identified a possible intervention. A drug called Zileuton, currently used for asthma, blocked the production of leukotrienes in the gut and protected mice from severe allergic reactions after eating allergens. It didn’t work for reactions triggered in other ways, suggesting this pathway is specific to what happens in the digestive system.
While the research is still in early stages and hasn’t been tested in people, it highlights a possible new way to prevent the most dangerous allergic responses. For families managing food allergies, this could someday mean more than avoiding trigger foods; it might involve protecting the body from within.
Until then, experts stress that the safest strategies remain the same: know your allergens, read labels carefully and carry emergency medication like an epinephrine auto-injector if you’re at risk. But as our understanding of how food interacts with the immune system grows, so does the potential for nutrition and medicine to work together in keeping those with allergies safe.
This work was supported by the National Institutes of Health, the Howard Hughes Medical Institute, the Food Allergy Science Initiative and the Blavatnik Family Foundation.