Stojkovic Andjelkovic, AndjelkaSimovic, AleksandraBogdanović Z.Banković, DragićPoskurica, Mina2023-02-082023-02-0820160370-8179https://scidar.kg.ac.rs/handle/123456789/16327Introduction Urban life is often followed by immune dysfunction and loss of immune tolerance in the youngest children. Objective The study aimed to determine optimal time efficiency of a synbiotic (5×109 Lactobacillus acidophilus Rosell-52, Bifidobacterium infantis Rosell-33, Bifidobacterium bifidum Rosell-71) in controlling respiratory infections and wheezing disease. Methods We randomly selected a group of children younger than five years, hospitalized earlier, and classified them into three groups. Results The incidence of respiratory infection before the study was once a month, while after a threemonth supplementation with the synbiotic children rarely suffered from respiratory infections, and the state was maintained after six-month and nine-month supplementations with the synbiotic. The decreased incidence of respiratory infections was followed by a falling incidence of concomitant wheezing. A significant increase in tIgA serum was observed in all groups for only three months, the increase being the highest in children with recurrent respiratory infections accompanied by wheezing. After a ninemonth administration of the synbiotic, total IgE serum was lower in all groups of patients. Conclusion The optimal duration of administration of the synbiotic containing three probiotic cultures to provide effective control of the frequency of respiratory infections was three months, and six months were required to establish control of the frequency of wheezing. This synbiotic is useful for immunomodulation in children and is well-tolerated in young children.article10.2298/SARH1602038S2-s2.0-84961880671