Recent evidence demonstrate metformin-induced changes in the gut microbiota; however, the relationship between metformin treatment and the gut microbiota still remains unclear. A double-blind study, published in Nature Medicine, support for the notion that altered gut microbiota mediates some of the anti-diabetic effects of metformin. In this study, Teams from the University of Gothenburg in Sweden and the University of Girona in Spain recruited 40 people with newly diagnosed type 2 diabetes to placebo or metformin for 4 months.

The results were verified in a subset of the placebo group that switched to metformin 6 months after the start of the trial. Transfer of fecal samples (obtained before and 4 months after treatment) from metformin-treated donors to germ-free mice showed that glucose tolerance was improved in mice that received metformin-altered microbiota.

Researchers believe that by favoring foods which might help promote good gut bacteria, type 2 diabetes can be better controlled.

Read More