Intestinal Microbiota's Protective Role Against Type 2 Diabetes

High concentrations of intestinal bacteria may help protect against type 2 diabetes (T2D).

Indolepropionic acid is a metabolite produced by intestinal bacteria, and diets rich in whole grains and dietary fiber increase its production.

In a study published inScientific Reports, investigators compared 2 groups of individuals who participated in the Finnish Diabetes Prevention Study (DPS). At the study’s onset, all participants were overweight and had impaired glucose tolerance.

The investigators examined the serum metabolite profile of 200 individuals with impaired glucose tolerance who had either developedT2Dwithin the first 5 years or did not convert to T2D within a 15-year follow up.

To determine the differences between the groups, the investigators used a nontargeted metabolomics analysis. The greatest differences were observed in the concentrations of indolepropionic acid and certain lipid metabolites

The results of the study showed that high concentrations of indolepropionic acid in the serum acted as a protectant against diabetes. Furthermore, it appeared to promote insulin secretion by pancreatic beta cells.

In addition, the investigators found several new lipid metabolites whose high concentrations were associated with improved insulin resistance and reduced the risk of diabetes. The metabolites concentrations were also associated with dietary fiber: the lower the amount of saturated fat the higher the concentrations of metabolites.

Similarly, high concentrations of the lipid metabolites seemed to protect against low-grade inflammation.

“Earlier studies, too, have linked intestinal bacteria with the risk of disease in overweight people,” said author Kati Hanhineva. “Our findings suggest that indolepropionic acid may be one factor that mediates the protective effect of diet and intestinal bacteria.”

DPS was the first randomized, controlled, lifestyle intervention study to show that individuals with impaired glucose tolerance, T2D can be prevented by lifestyle changes. Changes include weight lost, increase in exercise, and dietary adjustments to include more whole grains, fruits, and vegetables.