Eating more fiber may help prevent type 2 diabetes by promoting beneficial gut bacteria and substances produced during metabolism, according to a new study.
A new study provides evidence of how the risk of diabetes can be reduced: The researchers have found that increased fiber intake promotes beneficial intestinal bacteria. The study results were recently published in the American Heart Association (AHA) journal “Circulation Research”.
Protective effects against diabetes
“Consistent evidence suggests that fiber intake has protective effects against diabetes, but exactly how this protection occurs remains unclear,” explains Dr. Zheng Wang, co-author of the study and research assistant professor in the Department of Epidemiology and Population Health at the Albert Einstein College of Medicine in New York City, in a statement.
Discovering the links between fiber, gut bacteria, metabolites and type 2 diabetes – a leading risk factor for heart disease, stroke and kidney disease – could lead to more effective prevention of the disease, says Wang.
For example, identifying which bacteria and metabolites in the body are associated with the risk of type 2 diabetes paves the way for personalized diets and treatments to improve the gut and metabolic health of at-risk people.
“Good” intestinal bacteria
The study examined data from more than 11,000 participants in the ongoing Hispanic Community Health Study/Study of Latinos. According to the Centers for Disease Control and Prevention (CDC), Hispanic adults in the United States are at higher risk of developing type 2 diabetes than the general population.
The researchers found that higher fiber intake was associated with certain “good” gut bacteria and certain beneficial metabolites in the blood – some of which were actually produced by gut bacteria.
These gut microbes and metabolites were associated with a lower risk of developing type 2 diabetes during an average follow-up period of six years.
Consume more fiber
“This is new evidence as to why higher fiber intake is beneficial, particularly in reducing the incidence of new-onset type 2 diabetes in Hispanic adults,” said Dr. Robert H. Eckel, Professor Emeritus of the Department of Endocrinology. Metabolism and Diabetes and Division of Cardiology at the University of Colorado Anschutz Medical Campus in Aurora. The doctor was not involved in the study that has now been published.
“The recommendations for higher fiber intake can be further promoted based on this study,” says Eckel.
Fiber is mainly found in fruits, vegetables, nuts, whole grain products and cereals. They cannot be broken down in the gastrointestinal tract and a large proportion of them pass through the body undigested. Their best-known job is to promote regular bowel movements.
Complex communication
However, the new research suggests that fiber may also feed bacteria in the gut.
“What really surprised us – and turned out to be the most interesting part of our study – was how complex the communication between gut bacteria and their human hosts is,” says Wang.
“We learned that bacteria can influence disease risk through a variety of mechanisms. The complexity was both surprising and fascinating, revealing the deep and nuanced interactions within our gut microbiome.”
According to the expert, laboratory studies are needed to investigate the underlying mechanisms.
“Important for metabolic health”
Although the study’s observational design means that cause and effect could not be proven, Wang says, “The results have high biological plausibility because some of the specific metabolites highlighted in this study can only be produced by bacteria and not the human body.”
The study also relied on participants’ self-reported fiber intake, which may influence the results as participants may not always perfectly remember or describe their diet.
Eckel said future research should examine how else fiber might exert its beneficial effects in the body, perhaps related to reducing inflammation, improving metabolism, and the secretion and action of insulin, a hormone that regulates blood sugar in the body.
“Fiber is important for metabolic health, and we are beginning to understand why,” says Eckel. (ad)
