Insulin resistance (IR) is an important problem of humanity, which leads to development of many metabolic disorders. Сurrently the pathogenic mechanism of the development of IR is not completely investigated. Nevertheless, there are some hypotheses explaining the development of this condition. These include such hypotheses as the hypothesis of thrifty genotype, thrifty phenotype, hormonal, stress, good and bad calories, chronic metabolic inflammation, microbiotic and integrated model suggested by Professor Rainer Straub. In this article, the microbiotic theory will be considered in detail, explaining the mechanism of the development of peripheral tissue insensitivity to insulin in dysbiosis due to amplification of transmission by proinflammatory molecules from the intestine to the bloodstream and activation of systemic inflammation, disruption of the “gut-brain-periphery” mechanism and impaired receptor interactions of active intestinal metabolites of the gut microbiota (GM) at the level of cells of metabolic organs. The value of this theory is that its factors affect all links in the pathogenesis of the development of IR, reflected in the integrated model of Professor Straub. In this review the influence of GM and metabolic processes of human body on the development of IR will be considered in detail, data from clinical studies about the influence of GM (its composition, active metabolites, individual bacterial strains) on the development of IR and the role of chronic metabolic inflammation in this process will also be presented. In addition, attention will be paid to bidirectional effects of GM and metformin, as well as to data from clinical studies on changes in GM in healthy people and people with IR under the influence of metformin and how GM affects the pharmacokinetics of this drug. The possibility of IR correction through the use of dietary fiber will also be considered.