Fiber to the Rescue in the Fight Against Type 2 Diabetes
The main health benefits of a balanced gut microbiome come from short-chain fatty acids (SCFAs), which are made by gut bacteria fermenting carbohydrates (such as resistant starch).
SCFAs provide energy for the cells lining the colon and play a role in the regulation of appetite and inflammation. Notably, a deficiency in gut SCFAs has been associated with type 2 diabetes.
A remarkable new study published in the journal Science shows that a diet high in diverse fibers promotes a select group of gut bacteria, which leads to better blood glucose control, greater weight loss and better lipid levels in people with type 2 diabetes.
In the six-year-long study, scientists randomized patients with type 2 diabetes into two groups:
- The control group was given standard patient education and dietary recommendations.
- The treatment group was given a large amount of a variety of dietary fibers while ingesting a similar diet as the control group.
Both groups took the drug acarbose to help control blood glucose.
The high-fiber diet included whole grains, dietary fibers, and prebiotics.
After only three months, patients on the high-fiber diet had a greater reduction blood glucose levels than the control group. Their fasting blood glucose levels also dropped faster, and they lost more weight.
When the researchers analyzed the microbiomes of the two groups, they found an exclusive group of 15 strains of SCFA-producing bacteria that were boosted by the high fiber diet.
The scientists think that these bacterial strains may be the key drivers for better health.
When supported by the high-fiber diet, these 15 bacterial strains became the dominant strains in the gut. The SCFAs produced by these bacteria helped to create a mildly acidic gut environment that reduced the bad bacteria and led to increased insulin production and better blood glucose control.
This research further supports the growing evidence that balancing the gut microbiome with dietary fiber and prebiotics is a beneficial approach for the management of type 2 diabetes.
Liping Z. et al. Gut bacteria selectively promoted by dietary fibers alleviate type 2 diabetes. Science, 2018; 359 (6380): 1151 DOI: 10.1126/science.aao5774