Impact of antidiabetic treatments must be taken into account in studying the gut microbiota

Research on gut microbiota (bacteria of the digestive tract) has for some years greatly contributed to advancing medical science. Within an international consortium, INRA scientists along with foreign colleagues have shown the impact of the antidiabetic treatment metformin on the gut microbiota of Type 2 Diabetes patients (T2D). The results, published in Nature on December 2, stress that the effects of this treatment need to be considered in the research focusing on the link between gut microbiota and T2D and, generally, other frequent chronic diseases.

Type 2 diabetes (T2D) is a disease showing a rising global prevalence, which is associated to the increase in obesity. Past studies have shown that in chronic diseases like T2D the composition and the function of gut microbiota are altered, which suggests a strong link between these diseases and gut bacteria. “However, in most of these studies, patients’ treatments were not taken into account as a potential factor altering the microbiota”, says Dusko Ehrlich, one of the main authors of the newly published study.

Researchers from INRA, with international teams, compared profiles (or signatures) of gut microbiota from diabetics. One group was treated with metformin, the main antidiabetic treatment, and the other didn’t have treatment. Gut microbiota samples came from 3 cohorts: Chinese, Swedish and Danish, from the MetaHIT project coordinated by INRA (2008-2012). A total of 784 people including 199 affected with T2D were thus studied.

Analyses showed that the 92 treated patients had a distinct microbiota from the 106 non-treated ones. “Patients treated with metformin had a mix of bacteria in their gut that resembled more to that of healthy people. Metformin therefor affects gut microbiota by partly improving bacterial diversity, which lacks in T2D people”, explains Dr. Ehrlich.

Scientists conclude that future research on the alteration of microbiota in T2D patients, or in other frequent chronic diseases, such as cardiovascular or neurological complications, must consider the effects of drug treatments.

Further info

http://presse.inra.fr/en/Resources/Press-releases/Intestinal-bacteria-linked-to-type-2-diabetes
http://presse.inra.fr/en/Resources/Press-releases/Rich-or-poor-in-gut-bacteria-we-are-not-all-equal-facing-obesity-associated-diseases

Reference

Kristoffer Forslund et al. Disentangling the effects of type 2 diabetes and metformin on the human gut microbiota. Nature, 2 December 2015. DOI: 10.1038/nature15766

Scientific Contact

S. Dusko Ehrlich
+33 1 34 65 25 10 - dusko.ehrlich@jouy.inra.fr
MetaGenoPolis http://www.mgps.eu/ 
Scientific Division “Microbiology and the Food Chain”
INRA Center of Jouy-en-Josas

Director of the Host-Microbiome Interactions Centre
King's College London Dental Institute
E-mail: stanislav.ehrlich@kcl.ac.uk

Press Relations

INRA News Office
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