Chinese scientists identify gut bacteria beneficial to type 2 diabetes patients

Chinese scientists have identified a guild of particular gut bacteria that can ferment dietary fibres to help control blood glucose of patients with type 2 diabetes. The study, published on Thursday in the journal Science, showed that a diversified high fibre diet can promote 15 strains of gut bacteria that produce short-chain fatty acids (SCFAs), which nourish gut epithelial cells, reduce inflammation, and play a role in appetite control. Many gut bacteria have the genes and the capacity to produce SCFAs from carbohydrate fermentation. Deficiency of SCFAs is known to be associated with type 2 diabetes.

Zhao Liping and colleagues at Shanghai Jiao Tong University randomised patients to treatment or control group, both having similar intake of energy and macronutrients, using acrabose as the medication for blood glucose control but the treatment group had extra amount of diverse fibres.

Throughout the 12-week treatment, the intervention group, given a large, diversified amount of dietary fibres from whole grains, traditional Chinese medicinal foods and prebiotics, experienced more significant and faster improvement in blood glucose control, greater weight loss, and better lipid profile compared to the controls. After taking the treatment diet for four weeks, patients had a new gut microbiota and kept the new gut microbiota for another eight weeks. This group of bacteria reached greater abundance and diversity, and the patients had lower acetylated hemoglobin levels which indicated better blood glucose regulation.

The study also showed that these beneficial effects of the high fibre diet were directly contributed by changes in the gut microbiota by transplanting baseline and end of trial gut microbiota from the same individual to germfree mice.

“It provides compelling evidence supporting increased intake of dietary fibres may benefit T2D patients,” Zhao told Xinhua Thursday. Then researchers identified a small group of bacterial strains that were likely to be the key drivers of patients’ clinical improvements: these bacteria out-competed others and became dominant members of the gut microbial community.

“We may target restoration of this guild of beneficial bacteria for better glycemic control in patients with type 2 diabetes. If you have lost most or all the members of the guild of these active SCFA producers, you may need a microbiota transplantation from a healthy donor whose microbiota profile best benefit you by providing those members missing in your gut,” Zhao said. The study showed that a dietary program that targets this beneficial guild of gut bacteria is a clinically effective “gut-specific” way to improve insulin secretion and therefore alleviates type 2 diabetes.