Researchers studying the gut microbiota have found that fiber supplements of all kinds can improve gut health.
While there are a variety of gut health-promoting fiber supplements on the market, a recent study found that regardless of the type of fiber supplement, everyone can benefit from it, although dieters low in fiber particularly benefit, according to Duke University researchers.
“The people who responded best ate the least fiber initially,” study leader Lawrence David, associate professor of molecular genetics and microbiology at Duke University, said in a press release.
Fermentable fiber (indigestible dietary carbohydrates that certain gut bacteria can digest) is an essential nutrient for a healthy body. When insects in the gut microbiome are fed a diet high in fermentable fiber, they produce short-chain fatty acids, which protect against gut disease, colorectal cancer, and obesity.
Specifically, gut microbes produce more short-chain fatty acid butyrate, which can improve the gut’s defenses against pathogens, reduce inflammation, and create a healthier gut lining. Fiber supplements can increase the production of short-chain fatty acids, including acids such as butyrate.
“We have evolved to depend on the nutrients our microbiomes produce for us,” Zack Holmes, co-author of two new fiber papers, said in a press release. “But with recent changes in diets to high-fiber foods, we’ve stopped feeding our microbes what they need.”
American adults consume only 20-40% of their recommended daily fiber intake. According to the study authors, a diet low in fiber could be the cause of problems such as obesity, cardiovascular disease, digestive disorders and colon cancer.
David and his team noticed that many fiber supplements seemed to be interchangeable. Since every individual is different, the researchers wanted to know if customizing supplements could produce better production of short-chain fatty acids.
Investigators tested 3 popular fermentable fiber supplements on 28 participants: inulin, dextrin (Benefiber) and galactooligosaccharides (Bimuno). Participants randomly took 1 of the supplements for a week, then took a week off so their microbiome could return to baseline, then took a new type of supplement for another week. This process was repeated for each of the 3 supplements.
The researchers found that the type of supplement didn’t matter for participants who were already consuming a lot of fiber at the time of the study. They also showed the fewest changes in their microbiome because they already had an optimal diversity of gut microbes.
Participants on an initially low-fiber diet also did not notice a difference between the type of supplement and its effectiveness. However, these participants experience higher production of healthy butyrate compared to participants on an initially high-fiber diet, according to the study authors.
David’s lab, supported by the US Office of Naval Research, performed a second study that explored fiber doses. According to this study, gut microbes positively altered their gene expression to digest food in just 1 day, showing that all fiber and more is good.
The study authors said there is no need to supplement with fiber because high-fiber foods are a healthy addition to any diet.
“People who were already eating lots of fiber, which comes from plants like beans, leafy greens and citrus fruits, already had very healthy microbiomes,” Holmes said in the press release.
It doesn’t matter which fiber you choose – just get more fiber! Eurke alert! July 29, 2022. Accessed August 1, 2022. https://www.eurekalert.org/news-releases/960356