Thursday, February 9, 2017

How Dietary Fiber Prevents Disease

So why, exactly, is it that we should consume a lot of fiber in our diet to remain healthy? Are refined fiber supplements just as good as, say, an "apple a day?"

Recently, an article in the journal Cell answer seems to verify some of the answers for us.

As the paper cited below indicates, research seems to confirm that dietary fiber provides nutrients for the inhabitants of our intestinal microbiome.  When dietary fiber is missing, then the microbes undergo a shift in populations and start consuming our GI mucus as an alternate source of nutrition.  That, as you might guess, reduces the thickness of the protective mucus—hus increasing the likelihood that pathogens can more easily attack the intestinal lining. Ouch.

Apparently, refined prebiotic fibers don't fix the problem.

Here are some highlights of the research article (quoted from their online preview):

  • Characterized synthetic bacterial communities enable functional insights in vivo
  • Low-fiber diet promotes expansion and activity of colonic mucus-degrading bacteria
  • Purified prebiotic fibers do not alleviate degradation of the mucus layer
  • Fiber-deprived gut microbiota promotes aggressive colitis by an enteric pathogen

Image for unlabelled figure

What can we use from this in teaching undergraduate A&P?

  • When asked by students about dietary fiber, you have more information from which to draw an answer.
  • When discussing any of these topics, you'll now have a bit more to add to your story:
    • nutrition
    • function of mucus
    • the human microbial system (or specifically, the GI microbiome)
    • how pathogens cause disease (or specifically, GI disorders)

Want to know more?

Veggies and Intact Grains a Day Keep the Pathogens Away

  • Francesca S. Gazzaniga. Dennis L. Kasper. Cell. Available online 17 November 2016
  • Brief preview of the M. Desai article cited below.

A Dietary Fiber-Deprived Gut Microbiota Degrades the Colonic Mucus Barrier and Enhances Pathogen Susceptibility

  • Mahesh S. Desai et al. Cell, Volume 167, Issue 5, 17 November 2016, Pages 1339-1353.e21
  • The detailed research article.

Microbiome articles

  • Kevin Patton. The A&P Professor. Various dates.
  • Collection of previous posts on this topic from this blog.

Photos: Youssef KH (top) Cell (bottom)