The long-standing advice is that everyone should get more fiber in their diet, but a new study suggests some benefit more than others.

A person’s gut microbiome appears to have some influence over the benefits a person derives from dietary fiber, researchers report in the journal Gut Microbes.

Evidence from the study shows that each person has a unique response to eating a resistant starch, which is a form of dietary fiber found in bread, cereals, green bananas, whole-grain pasta, brown rice and potatoes.

Some derive great benefit, while others experience little to no effect – and the difference appears to be tied to the diversity and composition of the microbes in their gut.

The upshot is that people might do better if doctors gave personalized advice on what type of fiber to eat, based on their gut microbiome, researchers said.

“Precision nutrition definitely has a use in determining what dietary fiber we should tell people to eat,” senior researcher Angela Poole, an assistant professor of molecular nutrition at Cornell University, said in a news release. “This is critical because we’ve had public messaging advising people to eat more dietary fiber for decades.”

High-fiber diets can help people remain regular, feel fuller longer, reduce high blood pressure, lower cholesterol levels and stabilize blood sugar levels, prior research has shown.

For the study, researchers recruited 59 people and fed them three different types of crackers over seven weeks. Two types of cracker contained different forms of resistant starch, while the third type contained an easily digestible control starch.

The team found that each person’s gut microbes seemed to help determine whether digestion of dietary fiber would create more short-chain fatty acids, which are associated with improved blood sugar and cholesterol levels.

Analysis of individual microbiomes could provide helpful nutritional advice, showing people in advance how their body might respond to different types of fiber, researchers concluded.

“Since there are many different types of dietary fiber and carbohydrates, a better strategy would be to collect data on each person and tell them which dietary fiber they can eat to get the most bang for their buck,” Poole said.

The findings were published June 24.

More information

Houston Methodist has more about the benefits of dietary fiber.

SOURCE: Cornell University, news release, June 25, 2024