The study of intestinal microbiome is a very relevant topic popular among researchers, and a large number of studies are conducted. Currently, the amount of data on the human intestinal microbiome is growing at a high rate, both in health and in various pathological conditions. With an increase in the amount of the accumulated data, there is an expanded understanding that the microbiome is a very complex system, parts of which are in close relationship with the host organism, and react to environmental factors, including diet and medication intake. Researchers find more and more data on the correlation between medications, intestinal microflora and extraintestinal diseases. This article provides an overview of the data available in modern literature on the peculiarities of the state of intestinal microflora in patients with osteoarthritis, its possible impact on the disease pathogenesis, as well as changes that occur in the microbiome during treatment of osteoarthritis, particularly when using nonsteroidal anti-inflammatory drugs.