Bile acids are important physiological agents required for the absorption, distribution, metabolism, and excretion of nutrients. In addition, bile acids act as sensors of intestinal contents, which are determined by the change in the spectrum of bile acids during microbial transformation, as well as by gradual intestinal absorption. Entering the liver through the portal vein, bile acids regulate the activity of nuclear receptors, modify metabolic processes and the rate of formation of new bile acids from cholesterol, and also, in all likelihood, can significantly affect the detoxification of xenobiotics. Bile acids not absorbed by the liver can interact with a variety of cellular recipes in extrahepatic tissues. This provides review information on the synthesis of bile acids in various parts of the digestive tract, its regulation, and the physiological role of bile acids. Moreover, the present study describes the involvement of bile acids in micelle formation, the mechanism of intestinal absorption, and the influence of the intestinal microbiota on this process.
Keywords: bile acids; bile salts; metabolism; regulation of bile acids.