Probiotic bacterial strains have a beneficial effect on the maintenance of healthy intestinal microflora that is important for good digestion and strong immunity. Probiotics protect against multiplication of pathogenic microbes, mainly bacteria and fungi, in the intestines and in the whole organism. Moreover, they play their role in prevention of the development of tumours and food allergies. They are suitable as a supplement to the antibiotic treatment; they are administered in the course of treatment and afterwards.