Gut bacteria use fiber to improve heart health in mice

Researchers are learning more about the connection between fiber, the gut microbiome and the heart. A study recently published in the journal Nature Microbiology seems to have revealed one mechanism in the relationship.

Summary: While we knew that fiber is associated with a lower risk of heart disease, doctors didn’t know why. Turns out, a particular gut bacteria seems to use fiber to reduce atherosclerosis and inflammation in mice.

The study: Researchers at the University of Wisconsin-Madison developed colonies of mice with Roseburia and without the bacteria. They then fed the mice diets high in fiber or low in fiber. Mice with Roseburia who ate a high-fiber diet suffered less atherosclerosis and inflammation.

The findings: A particular fatty acid, butyrate, is the mechanism through which a high-fiber diet protects the heart in mice. Butyrate is produced by the bacteria Roseburia.

Study conclusions: Reducing overall inflammation, particularly in the bloodstream, may be the key to reducing atherosclerosis.

Points to consider: Having a strong gut barrier, which prevents inflammatory molecules from leaching into the bloodstream, also reduces inflammation. Fiber from whole foods, not supplements, is the best way to support a healthy gut, researchers concluded.

Current RDAs: The recommended intake for total fiber for adults 50 years and younger is set at 38 grams for men and 25 grams for women, while for men and women over 50 it is 30 and 21 grams per day, respectively, because of decreased food consumption, according the National Academies of Sciences Engineering Medicine. The average American consumes 15 grams a day.

Don’t forget dairy. Foods like fat-free and low-fat milk, cheese, yogurt, and fortified soy beverages (soymilk) help to build and maintain strong bones needed for everyday activities.

Who and when: UW–Madison Professor of Bacteriology Federico Rey and postdoctoral researcher Kazuyuki Kasahara, with collaborators at the Wisconsin Institute for Discovery; the University of California, Los Angeles; and the University of Gothenburg in Sweden.

Authors: UW–Madison Professor of Bacteriology Federico Rey and postdoctoral researcher Kazuyuki Kasahara

Published: Nature Microbiology, Nov. 5, 2018

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