How Fiber Promotes Intestinal Health

By Michael A. Smith, MD

Fiber is one of the most researched nutrients on the market. Published studies from around the globe have highlighted the benefits of a high fiber diet — benefits like protection from cancer, a healthy heart and even weight loss.

But could fiber actually promote beneficial shifts in gut bacteria, leading to better intestinal health? Well, new research seems to say yes.

This is important because specific species of gut bacteria play a major role in human health. As a matter of fact, certain bacteria can aid in digestion of food, absorption of nutrients and elimination of wastes.

Fiber Ferments in Your Gut

When fiber undergoes fermentation, they produce short-chain fatty acids and other metabolites that can encourage the growth of healthy or “friendly” bacteria. Researchers at the University of Illinois published a report describing this link between fermentation of fiber and the resulting growth of bacteria.1 They wrote that the metabolism of fiber has tremendous benefits.

In an epidemic of metabolic disorders and diabetes, a healthy gut flora could be exactly what we need. The researchers pointed out that people who maintain a proper gut flora are less likely to develop diabetes and intestinal disorders, like inflammatory bowel disease. They believe this is a key reason for all of us to eat more fiber.

But as always, the researchers caution about jumping to conclusions. Before anyone can make definitive treatment claims for fiber and intestinal diseases, large-scale, controlled human studies need to be conducted.

Fiber Positively Affects Bacterial Ecosystems

The new research coming out of the University of Illinois and published in the Journal of Nutrition shows that fiber has a significant effect on the relative abundance of bacteria in your gut.

The researchers believe that we should be able to identify specific types of fiber that best influence the abundance of healthy gut bacteria. In a sense, we could target the growth of the most beneficial species and optimize not only intestinal health, but also overall health.

Dr. Kelly Swanson, the lead investigator, said, “When we understand what kind of fiber best nurtures these health-promoting bacteria, we should be able to modify imbalances to support and improve intestinal health.”

The two fibers they studied were polydextrose and soluble corn fiber. Now don’t get too wrapped up in the types of fiber they used. What’s really interesting is that they were able to show that specific types of fiber can produce specific shifts in the type of bacteria in your gut.

This means that in the near future, fiber and probiotic combinations could be personalized based on your own specific gut flora. This has huge implications for people suffering from metabolic disorders and intestinal diseases.

For example, Dr. Swanson said, “One type of bacteria that thrived as a result of the types of fiber fed in this study is inherently anti-inflammatory.” This means that a fiber like polydextrose could be beneficial for people with inflammatory bowel disease or IBD. Again, as you can see, this could lead to a personalized and highly targeted fiber and probiotic combination for IBD.


  1. J Nutr. 2012 Jul;142(7):1259-65. Epub 2012 May 30. (


woman's health said...

I love kefir, but since I am now vegan, I am looking into trying to make coconut kefir. I just found out that fermented foods are higher in histamines, which can produce symptoms similar to allergies if their levels are too high. Since my wife has been having terrible allergies, I am worried that fermented food would only make it worse for her.

Jon Sam said...

Fiber is a natural substance found in fruits, vegetables and grains. It is an essential part of healthy digestion. Additionally, fiber adds bulk to your diet, making you feel fuller sooner and longer. It helps aid digestion and can prevent constipation. :)

check this out said...

Organic food is good to health.

Post a Comment

All Contents Copyright ©2020 Life Extension® All rights reserved.
Privacy Notice | Terms of Use
These statements have not been evaluated by the Food and Drug Administration.
These products are not intended to diagnose, treat, cure, or prevent any disease.
The information provided on this site is for informational purposes only and is not intended as a substitute for advice from your physician or other health care professional or any information contained on or in any product label or packaging. You should not use the information on this site for diagnosis or treatment of any health problem or for prescription of any medication or other treatment. You should consult with a healthcare professional before starting any diet, exercise or supplementation program, before taking any medication, or if you have or suspect you might have a health problem. You should not stop taking any medication without first consulting your physician.