Mice fed a fiber-rich diet were more resistant to allergy-induced airway inflammation, thanks to happy gut bacteria that produce fatty acids, which calm the immune system. Sophie Bushwick reports
It's important to trust your gut. Because the stomach, and the food put into it, can influence the entire body. For example, a new study finds that mice that eat lots of fiber have stronger resistance against asthma-like attacks.
For two weeks, lab mice ate one of three diets: low-fiber, or regular chow, or food supplemented with fiber-rich pectin. Then the mice were exposed to allergy-inducing dust mites. And the low-fiber rodents suffered from increased airway inflammation, while the high-fiber group experienced less of an asthmatic response.
Seems that fiber supports gut bacteria that produce anti-inflammatory molecules called short chain fatty acids. These molecules then enter the bloodstream, where they can influence the immune system. An over-reactive immune system can play a role in allergies and asthma. But the fatty acids can calm down the immune reaction. The work is published in Nature Medicine. [Aurélien Trompette et al., Gut microbiota metabolism of dietary fiber influences allergic airway disease and hematopoiesis]
Directly injecting the mice with a short chain fatty acid had a similar anti-inflammatory effect. But mice probably prefer fiber to a series of shots—and it still helps them breathe easy.