Currently, the fast pace of life, changes in consumers’ habits, and the trend toward a healthy lifestyle around the world create the need for new healthy foods for immediate consumption. In this regard, the production of snacks with high nutritional value, as well as giving them functional properties through the use of various types of raw materials, seems promising. The choice of components following the physiological needs of various population groups in snack production allows getting new specialized food products, which improves people's quality of life and health. The most promising is the production of functional snack bars by combining vegetable and dairy raw materials. It is promising to use mare’s milk as a dairy raw material. The clinical efficacy of the new fruit-protein bars based on mare’s milk (FBBs) was tested on 25 volunteers aged 25-35 years for 60 days. The control group consisted of 15 people who received two KDV fruit and nut bars for 60 days, the nutritional and energy value of which was comparable to the snacks studied. Before and after taking snacks, blood biochemical and immunological parameters were evaluated. The results indicate a positive effect of new snacks based on mare’s milk on performance indicators, the state of cellular immunity, blood parameters, biochemical parameters, and antioxidant status. There is a decrease in fat mass, intracellular and extracellular fluid levels, and a reducing the number of final and intermediate lipid peroxidation products. The blood level of haemoglobin, erythrocytes, platelets, hematocrit, and all classes of immunoglobulins increased. Specialized functional protein bars, enriched with dry mare’s milk, can be recommended to various categories of the population experiencing intensive physical activity and psychoemotional stress to increase their adaptive capabilities and performance.