Probiotics are living microorganisms present in food, which after being consumed in a specific amount, have positive effect on the organism by improving the equilibrium in the intestinal ecosystem. There is an increasing application of probiotics in prevention and treatment of diseases in paediatric patients (e.g. diarrhoea, eradication of Helicobacter pylori infection, lactose intolerance, allergic eczema, atopic dermatitis, respiratory tract infections, food allergy, inflammatory bowel diseases). The positive effect of probiotics on the immune system is unquestionable. However, in view of individual reports on their adverse reactions (bacterial infections, fungemia, anaphylactic symptoms) it is necessary to apply them with care to some patients.

Key words: probiotics, pediatrics, safety of therapy