Changing the diet of people with type 2 diabetes to include more high-fibre foods has been found to promote the growth of beneficial gut bacteria that are linked to a direct effect on improved blood glucose control, greater weight loss and better blood fat levels.

The gut microbiota is one of the hottest topics in research. Now researchers are looking at what role these diverse microbes in our gut can play in helping to manage type 2 diabetes. The rationale to look at this comes from the role that bacteria play in breaking down and fermenting dietary fibres. The by-product of this fermentation is a range of compounds called short-chain fatty acids (SCFAs). These SCFAs help support the health of gut cells, reduce inflammation, control appetite and potentially help regulate blood glucose.

Lower SCFAs levels are seen in people with type 2 diabetes, leading researchers to question if promoting the production of more SCFAs by a higher fibre diet could help manage diabetes.

In new research from China, people with type 2 diabetes were randomised into two groups. The active treatment group received detailed information on including more specific types of fibre in their diet from a diversity of sources. The diet included whole grains, traditional Chinese medicinal foods rich in dietary fibres and prebiotics which are ‘food fertiliser’ for gut bacteria which produce SCFAs. The control group received standard patient education and dietary recommendations that had a more limited focus on high-fibre foods.

After 12 weeks on the diet program, people following the high-fibre diet had a greater improvement in their blood sugar control as measured by glycosylated haemoglobin (HbA1c). They also had a lower fasting blood glucose levels and as a bonus lost more weight compared to the control group.

When the research team looked at specific strains of bacteria that are known to produce SCFAs, 15 of them were present in greater numbers suggesting they were thriving off the greater amount of fibre to feed on. A health benefit of SCFAs comes from the mildly acidic gut environment they create which helps compete out more detrimental bacteria.

Implications

The study supports establishing a healthy gut microbiota as a novel nutritional approach for preventing and managing type 2 diabetes. Eating more of the right types of dietary fibres can help boost beneficial gut microbiota, which could bridge the health link between such diets and an improvement in type 2 diabetes.

Last Reviewed: 18/11/2018

© Norman Swan Medical Communications.



References

Zhao L et al. Gut bacteria selectively promoted by dietary fibers alleviate type 2 diabetes. Science 2018;359:1151-1156.