Not the type of fodder, but the quantity is crucial -

fiber for health

Fiber improves intestinal health and protects against obesity, cardiovascular disease and colon cancer, among other things. But does this also apply to all types of fermented fiber and what about fiber supplements?

Two new studies involving experts from Duke University and Penn State University have looked at how different types of fiber and total fiber intake affect healthy adults. The results have been published in the journals "Microbiome" and "ISME Journal".

What makes fiber so healthy?

Dietary fiber has a variety of beneficial effects. For example, they improve gut health and protect against obesity, cardiovascular disease, digestive disorders and colon cancer, the researchers explain.

Fiber only makes bowel movements easier, and fermentable fiber is also an important source of nutrients needed by beneficial gut microbes.

More short-chain fatty acids thanks to fiber

When gut bacteria get enough fiber, they produce more short-chain fatty acids. These are known to protect against the development of intestinal diseases, colon cancer and even obesity, the team explains.

With more dietary fiber, gut bacteria produce more of a special fatty acid called butyrate. This serves as fuel for human intestinal cells, the researchers continue.

Butyrate has been shown to improve the gut's resistance to pathogens, reduce inflammation and promote healthier cells lining the gut.

Dietary fiber intake has dropped sharply

“We have evolved to depend on the nutrients our microbiome produces for us. But with the recent shift in diet away from fiber-rich foods, we've stopped giving our microbes what they need," study author Zack Holmes said in a press release.

Which dietary fibers have been analyzed?

In one of the new research papers, the effects of three main types of fermentable fiber were examined. These were inulin, dextrin (Benefiber) and galactooligosaccharides (GOS).

First, 28 study participants were divided into three groups. They then received a week-long dietary supplement of one of the three fibers in a different order. There was a one-week break between preparations.

Personalized fiber supplements?

Because there is a wide variety of dietary fiber supplements, researchers wanted to see if it made sense to customize fiber supplements for different people.

Because different fermentable fibers have different effects on the production of short-chain fatty acids in different people, according to the research team.

Butyrate production increased by a similar amount

However, there was no significant difference in the effects of taking the different dietary supplements. All had a similar positive effect.

“We found no major differences between the dietary fiber supplements tested. In fact, they seemed interchangeable,” said study author Lawrence David of Duke University. Whichever fiber you choose , the microbiome will produce more butyrate.

Participants who had consumed the most fiber before the study showed the smallest changes in their microbiome. According to David, this is likely because these people were already carrying a "healthier" population of gut bacteria.

However, participants who had previously consumed the least fiber showed the greatest increase in butyrate, regardless of fiber type.

Adapted gut microbes in a day

In a second study they conducted, the team found that within a day, gut microbes reacted to the new fiber and the populations of microbes in the gut changed dramatically.

The researchers found that the first dose stimulated gut microbes to consume fiber. The second dose showed that gut microbes digest fiber very quickly.

The main thing is dietary fiber - it doesn't matter which!

“If you're low in fiber, it's not worth worrying too much about the type of fiber you add. It's just important that you find something that works for you in a sustainable way,” says the author of the Jeffrey Letourneau study from the Duke University School of Medicine.

Studies show that it makes sense to make sure you get enough dietary fiber because it's good for your health. It doesn't have to be dietary supplements, the researchers point out that fiber-rich foods like beans, leafy vegetables or citrus fruits can also help. (as)

Author and source information

Show now

This text corresponds to the specifications of the specialized medical literature, medical guidelines and current studies and has been verified by health professionals.


Zachary C Holmes, Max M Villa, Heather K Durand, Sharon Jiang, Eric P Dallow, et al. Microbiota responses to different prebiotics are conserved across individuals and associated with habitual fiber intake; in: Microbiome (published 2022-07-29), MicrobiomeDuke University: It doesn't matter which fiber you choose - just get more fiber! (published 7/29/2022) Duke University Jeffrey Letourneau, Zachary Holmes, Eric Dallow, Heather Durand, Sharon Jiang, Verónica Carrion, Savita Gupta, Adam Mincey, Michael Muehlbauer, James Bain, Lawrence David: Ecological Memory of Prior Nutrient Exposure in the Good Human Microbiome; in: ISME Journal (published 07/23/2022),

Important Note:
This article contains general advice only and should not be used for self-diagnosis or treatment. It cannot substitute a visit to the doctor.