Metformin is the most commonly prescribed medication for Type 2 Diabetes. Although it is well known to be very effective in lowering blood glucose levels, how it does so is still unclear.
Now, a new study by Prof. Fredrik Backhed and colleagues has revealed that Metformin may work by changing the composition of the bacteria in the gut.
The research involved 40 patients who were newly diagnosed with diabetes and had never previously taken metformin before. Each patient was randomly assigned to take metformin or a placebo.
Examination of the fecal samples taken from these participants two months after treatment found that patients who received metformin had an increased abundance of beneficial bacteria in their gut, such as Akkermansia muciniphila and Bifidobacterium adolescentis. These bacteria are known to lower blood sugar levels, decrease body fat, and improve metabolism.
Prof. Backhed and his colleagues further showed in cultured cells (i.e. cells grown in a flask) that indeed, these strains of good gut bacteria grow faster in the presence of metformin.
Finally, the researchers took faeces from metformin-treated patients, and transferred them to mice. They found that mice that received the fecal transplant showed improved glucose tolerance, even though they were never directly treated with metformin themselves.
This suggest that the change in gut microbiome play an important role in Metformin’s effects in lowering blood glucose levels.
There are currently 14 ongoing clinical trials exploring whether probiotics treatment might be effective against various types of diabetes.