An asthma drug blocks allergic reactions to food.

A drug approved for years to treat asthma may offer new protection against food allergies, according to a study published in the journal Science conducted at Northwestern University in Chicago (USA). The drug, zileutonal, by blocking a newly identified pathway in the body, completely prevented severe allergic reactions to food in mice.

The treatment resulted in mice that previously had a 95% chance of suffering from anaphylaxis becoming 95% protected after receiving the drug before being exposed to peanut extract, one of the most common allergens.

The key to this discovery was the discovery of a little-studied gene, DPEP1, which controls an inflammatory molecule in the gut: cysteinyl leukotrienes. These compounds are already targeted by asthma medications such as Zileuton. By blocking this pathway with the drug, the researchers stopped the allergic reaction at its source.

" It's a completely new and original approach to treating food allergies ," explains Adam Williams, co-author of the study.

The research has already taken the next step: in July, the team began an initial clinical trial in people to evaluate whether the treatment is equally effective outside the laboratory.

Currently, options for treating food allergies are limited, expensive, and don't work for everyone. If the trials are successful, the medication could become a simple alternative: a pill taken before potential exposure to the allergen, as a preventative measure.

The discovery also helps explain why some people test positive for food allergies but don't experience symptoms after eating the food.

"This pathway could be the reason why some people are protected despite their diagnosis," says Stephanie Eisenbarth, co-author of the study.

Furthermore, the same issue of ' Science ' includes a companion article that also identifies the central role of leukotrienes in food allergy, using a different approach.