18-05 Segment 2: Fiber and the Gut

Copyright: baibakova / 123RF Stock Photo


Fiber is an important part of a daily diet, but many people do not know what fiber  does for the body. Dr. Hannah Holscher, Assistant Professor of Nutrition at the University of Illinois-Urbana-Champaign, explains that fiber is a non-digestible carbohydrate that is found in plants which human enzymes cannot break down, so the body relies on microbes.

But why is fiber so important for the human body? According to Dr. Andrew Gewirtz, Professor of Biomedical Sciences at Georgia State University, fiber helps nourish beneficial bacteria in the intestine that is needed to aid digestion, keep the immune system strong, and block potential pathogens. Without fiber in your diet, this bacteria becomes malnourished, decreasing the number of them present. Dr. Gewirtz explains that discoveries from experiments on mice show that this decrease in bacteria can lead to a number of health issues.

It is important to maintain a high fiber diet in order to ensure proper nourishment of these beneficial bacteria. However, many people stick to one type of fiber rather than trying a few. People should eat a variety of fruits, vegetables, and other high-fiber foods to give their bodies more than one kind of fiber. While it can be difficult to consume the suggested amount of fiber everyday, the positive health benefits are worth it.


  • Dr. Hannah Holscher, Assistant Professor of Nutrition at University of Illinois-Urbana-Champaign
  • Dr. Andrew Gewirtz, Professor of Biomedical Sciences at Georgia Sate University

Links for more information:

Share this:

Stay in the loop! Follow us on Twitter and like us on Facebook! Subscribe and review on iTunes!

15-07 Story 1: The Gut Microbiome


Synopsis: Scientists are learning that the bacteria living inside us, most notably in the intestines, influence our bodies far more than previously suspected. Our microbiome influences many other organs, particularly the liver, brain, and immune system. Different mixes of these bacteria may account for a great deal of the variability among people, particularly in our weight.

Host: Reed Pence. Guests: Dr. Jack Gilbert, Group Leader, Microbial Ecology, Argonne National Laboratory; Dr. Rob Knight, Professor of Pediatrics and Computer Science & Engineering, University of California, San Diego

Click here for the transcript.