You’ve probably heard it before—fiber-rich foods are an important part of a balanced diet. There’s a reason the saying goes, “an apple a day keeps the doctor away”—we all want to “stay regular.” Scientists recently discovered another reason to have a fiber-rich diet and surprisingly enough it’s related lung health.

Researchers studied mice on three different diets—low-fiber, regular chow, or food with fiber supplements—and found that the mice with a high-fiber diet had a stronger resistance to asthma-like attacks. When mice on the low-fiber diet were exposed to dust mites, a known allergen, they experienced increased airway inflammation. The high-fiber diet mice showed a lesser asthmatic response to the dust mites.

Fiber supports gut bacteria that in turn produces anti-inflammatory molecules. When these molecules enter the bloodstream, they help regulate the immune system, which is important because an over-reactive immune system negatively affects allergies and asthma. Need more fiber in your life? Try foods like nuts, apples, bulgur wheat, kiwis, and chia seeds.