INTRODUCTIONIn recent years, the implementation of the healthy food policy has been one of the important trends in health maintenance, disease prevention, restoration of disturbed functions of the body, and active human longevity. Food is the most powerful factor influencing the human body state. It affects all systems and organs continuously throughout life [1].Food is a source of energy and substances necessary for growth, development, and other human vital processes. Food products should improve metabolism and body's resistance to adverse environmental effects as well as to have physiological, revitalizing, and preventive effects on the human body [2].An important role in maintaining health and human performance is played by the adequate and regular supply of the body with all the nutrients [3, 4]. Thus it is necessary to take into account that the total number of incoming biologically assimilable nutrients should not exceed the daily physiological need of a healthy person since it can be accompanied by undesirable side effects.As part of the development of the optimum nutrition concept a new branch of science was formed, i.e., the functional food. It includes the development of theoretical bases of production, sale, and consumption of functional foods.Functional foods are conventionally divided into main groups with respect to specifics of the production process: conventional foods containing a significant amount of the native physiologically functional ingredient, products with technologically reduced harmful components, and products enriched with prebiotics and probiotics, antioxidants and vitamins, micronutrients and flavonoids, minerals and other substances essential to the human body [5].A current area of research is the development of technologies for manufacturing fermented milk products with probiotic properties [6]. It is believed that at the beginning of the XXI century dairy products with probiotic cultures will occupy half of the existing market of chemical drugs and thereby solve the problem of prevention and treatment of many human diseases [7, 8, 9].The use of probiotics based on live microorganisms from the normal human microflora is an important element of the concept of healthy nutrition of the population and one of the most effective ways to prevent human gastrointestinal tract disorders and treat thereby developing disorders of digestive, immune, and endocrine systems [10, 11].The possibility of application of probiotics in dairy products is determined by the availability of milk, its low cost, multicomponent composition, possibility of modification, and easy fractionation [12]. In introducing probiotic bacteria (before or after souring), it is necessary to take into account that their viability is a valid unit of measurement of the probiotic activity. Therefore, the content of bifidobacteria in probiotic products should be standardized [13].In the fermentation of raw milk the focus should be made on the selection of strain of starter microflora. Poor development of bifidobacteria in milk is associated with oxygen dissolved in it, so the co-culture of bifidobacteria with lactic acid bacteria has a number of advantages. Lactobacilli bind oxygen dissolved in milk and thus create anaerobic conditions favorable for the growth of bifidobacteria.Numerous studies [14, 15] found that dairy products fermented with probiotic bifidobacteria and lactobacilli stimulate the immune system and protective functions of the body and supply a number of essential amino acids and B vitamins. Their ability to reduce the level of urea and cholesterol in the blood as well as anticarcinogenic and antimutagenic activities which perform protective and detoxificating functions were found. Bifidobacteria contribute to the absorption of lactose [15].