The Effect of a Multistrain Probiotic on Metformin Tolerance and Efficacy With Microbiota and Stool Metabolome in Insulin-resistant Women - a 12-week Randomized, Placebo-controlled, Double-blind Study

The goal of this study is to evaluate the efficacy of metformin on insulin sensitivity and vascular endothelial function with respect to gut microbiota and metabolome in women with established insulin resistance and its tolerance after 12 weeks of probiotic therapy. The hypothesis is probiotic therapy in women with established insulin resistance undergoing metformin treatment increases the drug\'s efficacy to improve insulin sensitivity and intestinal endothelial function, and reduces gastrointestinal side effects. Study participants will be randomly assigned to 2 groups, taking a probiotic (GS) or a placebo (GP). The randomization scheme will be computer-generated using permuted blocks of block size 4.