Probiotics in Metformin Intolerant Patients With Type 2 Diabetes

Metformin, the first-line drug in the treatment of type 2 diabetes (T2DM), may cause dose dependent undesirable side-effects like diarrhea, abdominal pain, nausea or bloating which may affect up to 20 % of patients treated with this drug. The mechanism of the gastrointestinal intolerance in patients treated with metformin is poorly understood. The number of studies on this topic increases and data are mounting that metformin treatment is associated with changes in gut bacterial composition. Among other drugs, metformin also leads to enrichment of short chain fatty acids (SCFAs) producing microbiota which exert positive influence on the human metabolic state. It has been shown that the therapeutic effect of metformin depends on the microbiota and metformin's main site of action in humans is the intestine. It is also known that patients with T2DM, in general, show evidence of gut dysbiosis followed by alterations of an intestinal barrier leading to an increase in intestinal permeability and elevated inflammatory state. Therefore, it has been speculated that metformin's versatile effect mediated through the gut microbiota is responsible not only for its therapeutic effect but also for its undesirable digestive symptoms. Probiotics, defined as "live microorganisms, that when administered in adequate amounts, confer a health benefit on the host", may have the potential to modulate the gut bacterial composition. This is why the investigators hypothesize that it may also reduce the intensity of adverse effects associated with metformin use. The investigators have chosen Sanprobi Barrier multi-strain formula probiotic because it is identical, in relation to bacterial strains and number, to Ecologic® BARRIER which has been proven in in vitro studies to improve the function of epithelial barrier of the intestine. It was also shown that 12-week administration of strains included in Ecologic® BARRIER in obese postmenopausal women improved intestinal barrier permeability mar