Are Dietary Fiber, the Gut Microbiome, and Asthma Connected?

An association exists between more dietary fiber (particularly soluble fiber) and fewer gut inflammatory disorders. A Swiss team has identified some mechanisms by which high–soluble fiber diets might protect against gut inflammation and another inflammatory disease: allergic airway disease.

The team raised mice on low-, regular-, or high-fiber diets; the three groups of mice were exposed repeatedly to dust mite allergens. The high-fiber group produced the most short-chain fatty acids (SCFAs) in the gut, with consequently higher levels in the blood. Particular species of gut microbes (particularly in the Clostridium genus) were responsible for digesting soluble fiber into SCFAs. Increased blood levels of SCFAs were associated with decreased a…