Intestinal bacteria may protect against diabetes

April 11, 2017

A high concentration of indolepropionic acid in the serum protects against type 2 diabetes, shows a new study from the University of Eastern Finland. Indolepropionic acid is a metabolite produced by intestinal bacteria, and its production is boosted by a fibre-rich diet. According to the researchers, the discovery provides additional insight into the role of intestinal bacteria in the interplay between diet, metabolism and health.

The findings were published in Scientific Reports. The study was carried out in the LC-MS Metabolomics Centre of the University of Eastern Finland together with a large number of partners from Finnish and Swedish research institutes.

The study compared two groups participating in the Finnish Diabetes Prevention Study, DPS. At the onset of the study, all participants were overweight and had impaired glucose tolerance. The researchers investigated the serum metabolite profile of 200 participants with impaired glucose tolerance, who either developed type 2 diabetes within the first 5 years, or did not convert to type 2 diabetes within a 15-year follow-up. The differences between the groups were analysed by non-targeted metabolomics analysis. Instead of focusing on just a few pre-defined markers, metabolomics analysis allows for the determination of the study participants' metabolic profile, i.e. the concentrations of several metabolites.

The greatest differences in the metabolic profiles of those who developed type 2 diabetes and those who didn't were observed in the concentrations of indolepropionic acid and certain lipid metabolites.

A high concentration of indolepropionic acid in the serum was discovered to protect against diabetes. Indolepropionic acid is a produced by . A diet rich in whole grain products and dietary fibre increased the indolepropionic acid concentration.  A higher concentration of indolepropionic acid also seemed to promote insulin secretion by pancreatic beta cells, which may explain the protective effect.

In addition to the DPS data, the association of indolepropionic acid with the risk of diabetes was also studied in two other population-based datasets: in the Finnish Metabolic Syndrome In Men Study, METSIM, and in the Swedish Västerbotten Intervention Project, VIP. In these datasets too, indolepropionic acid was discovered to protect against diabetes.

The study also identified several new lipid metabolites whose high concentrations were associated with improved insulin resistance and reduced risk of diabetes. The concentrations of these metabolites were also associated with dietary fat: the lower the amount of saturated fat in the diet, the higher the concentrations of these metabolites.  Similarly to indolepropionic acid, high concentrations of these lipid metabolites also seemed to protect against low-grade inflammation.

"Earlier studies, too, have linked intestinal with the risk of disease in overweight people. Our findings suggest that indolepropionic may be one factor that mediates the protective effect of diet and intestinal bacteria," Academy Research Fellow Kati Hanhineva from the University of Eastern Finland says.

A direct identification of intestinal bacteria is a complex process, which is why identifying the metabolites produced by intestinal bacteria may be a more feasible method for analysing the role of intestinal bacteria in the pathogenesis of, for example, diabetes.

The Finnish Diabetes Prevention Study was the first randomised, controlled lifestyle intervention study to show that in persons with impaired glucose tolerance, type 2 can be prevented by lifestyle changes. The most important lifestyle changes included weight loss, more exercise and dietary adjustments to include more whole grain products, fruits and vegetables.

Explore further: High serum omega-6 polyunsaturated fatty acid concentrations linked to lower risk of type 2 diabetes

More information: Vanessa D. de Mello et al. Indolepropionic acid and novel lipid metabolites are associated with a lower risk of type 2 diabetes in the Finnish Diabetes Prevention Study, Scientific Reports (2017). DOI: 10.1038/srep46337

Related Stories

Altered purine metabolism linked to depression

May 17, 2016

People suffering from major depressive disorder may have altered purine metabolism, according to a new study from the University of Eastern Finland and Kuopio University Hospital. Purines are nitrogenous compounds that serve ...

Metabolites linked to renal decline, time to ESRD in T1DM

January 19, 2017

(HealthDay)—Serum levels of seven modified metabolites are associated with renal function decline and time to end-stage renal disease (ESRD) among patients with type 1 diabetes (T1D), according to a study published online ...

Recommended for you

Designing better drugs to treat type 2 diabetes

May 18, 2017

Research led by the University of Adelaide is paving the way for safer and more effective drugs to treat type 2 diabetes, reducing side effects and the need for insulin injections.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.