High fiber diets could control diabetics’ blood sugar better than we ever realized, new research suggests.
For decades, nutritionists have urged everyone – diabetes diagnosis or not – to load up on leafy greens, whole grains, and bananas since their fiber content keeps digestion stable and smooth.
But new research by Rutgers University has found fiber plays a far more active role than ever recorded in nurturing the gut bacteria that control blood sugars and fats.
The findings could pave the way to personalized high-fiber diets as a first-line treatment for the disease, which affects 29.1 million Americans.
The researchers say it could also help to curb the rapidly climbing rates of diabetes diagnoses – driven by the obesity crisis – if more non-diabetics take up a high-fiber diet as well.
New research by Rutgers University has found fiber plays a far more active role than ever recorded in nurturing the gut bacteria that control blood sugars and fats
‘Our study lays the foundation and opens the possibility that fibers targeting this group of gut bacteria could eventually become a major part of your diet and your treatment,’ said Professor Liping Zhao, a microbiologist at Rutgers University-New Brunswick in New Jersey.
Type 2 diabetes can lead to a range of devastating problems from heart attacks and strokes to kidney failure, blindness and losing a limb.
It develops when the pancreas makes too little of glucose controlling insulin, or when the body doesn’t use the hormone well.
Gut bacteria produce short-chain fatty acids that nourish intestine lining cells, reducing inflammation and helping to control appetite.
A shortage has been associated with type 2 diabetes and other diseases.
Now, however, evidence is building that one of the most widespread and deadly medical conditions of the modern age, which is linked to lifestyle factors like obesity, can be combated through diet.
Foods high in fiber boost gut bacteria that control blood sugar by breaking down carbohydrates.
Last year, a study showed losing weight by following an 800-calorie-a-day eating plan for eight to 12 weeks can send the disease into remission. The more weight participants lost, the more likely patients were to see an end to the condition.
But while previous research has found increasing dietary fiber consumption may relieve type 2 diabetes, Professor Zhao and colleagues say they have finally unlocked the mechanism to explain why and how.
Professor Zhao’s pioneering high-fiber diet, which included whole grains and Chinese medicinal foods, followed participants for six years and found it re-balanced their gut bacteria.
The study found dramatic improvements in those who followed the eating plan – in less than three months.
They also lost more weight and had healthier blood fat levels.
Working with colleagues in China, patients were selected at random to go on the high fiber diet, which also included prebiotics that boost short-chain fatty acids.
A second group acted as a control, receiving standard advice and food recommendations.
All 43 participants consumed similar amounts of energy and major nutrients, and took the blood glucose drug acarbose.
After 12 weeks, the average reduction in blood glucose levels was greater in the 27 on the high-fiber diet than the 16 control subjects.
Their fasting blood glucose levels also dropped faster, and they shed more pounds.
Surprisingly, of the 141 strains of short-chain fatty acid-producing gut bacteria identified by state of the art sequencing, only 15 are promoted by consuming more fibres.
These are likely to be the key drivers of better health, explained the researchers. Bolstered by the foods, they became the dominant strains in the gut after they increased levels of the short-chain fatty acids butyrate and acetate.
These acids created a mildly acidic gut environment that reduced populations of detrimental bacteria and led to increased insulin production and better blood glucose control.
The researchers said the study published in Science supports establishing a healthy gut microbiota as a new nutritional approach for preventing and managing type 2 diabetes.
Professor Zhao said it suggests type 2 diabetes may be caused by the loss of a beneficial function in gut bacteria.
He explained: ‘In ecological terms, the production of short-chain fatty-acids (SCFA) from carbohydrate fermentation, which is needed to maintain human health, can be considered an ‘ecosystem service’ provided by the gut microbiota to human hosts.
‘Restoring or enhancing the lost or deficient function by reestablishing the functionally active ecological populations as ecosystem service providers (ESPs) is the key to a healthier microbiota, which can help alleviate disease.
‘Targeted promotion of the active SCFA producers as ESPs via personalised nutrition may present a novel ecological approach for manipulating the gut microbiota to manage type 2 diabetes and potentially other related diseases.’