Identifying a Misconception About Insoluble Fiber

This article is another one that practically wrote itself one afternoon – it is actually a Letter to the Editor

Title: Insoluble fiber and intestinal microbiota metabolism

Author: C Brotherton

Journal: Journal of Gastroenterology

Date: April 2015

Volume/Issue/Page: 50(4):491

For full text of my article, click HERE

The purpose for my article was to call attention to an unfounded bias against insoluble fiber in some research articles. I wrote the letter in response to a statement made in a research article, and that article is available by clicking HERE.

The statement to which I was compelled to respond was this:

Fermentable carbohydrates include pectins, hemicelluloses, gums, and prebiotic
substances including fructose and galactose-oligosaccharides that are not responsive to mammalian enzymes, but not what we typically think of as dietary fiber, such as
cellulose or wheat bran (page 788).


The truth is that cellulose and wheat bran do ferment, just at a lower percent (34%) compared to some other fibers. However, the fermentation that occurs when cellulose and wheat bran are eaten, happens farther along in the digestive tract. This truth is AMAZING for someone like me who needs short-chain fatty acids at the very end of my digestive tract. Short-chain fatty acids are products of fiber fermentation, and shifting fermentation further down the tract delivers these healing substances to just the right point of need for this Crohn’s-diseased colon.