Probiotic microorganismis were found to affect beneficiallythehostbyimprovingintestinalmicrobialbalance.They have also many benefitssuchasreducingtheriskofdiarrhea,normalizebowelmovements,enhancingimmunefunctions, reducing cholesterol levels, reducing the risk of eczema, protection from cancer and relief of lactose intolerance symptoms.Some probiotic properties of identifiedstrainsoflacticacidbacteria(21strains)whichisolatedfromhealthy breast-feeding infants were studied in the presence of different concentrations of bile salts (0.2, 0.3 and 0.4%) and different values of pH (4, 3 and 2). The results as compared to control revealed that 11 strains of Lb. fermentum and all strains of Lb. salivarius exhibited variant growth at all concentrations of bile salts. On the other hand, all strains of Lb. fermentum and 8 strains of Lb. salivarius were tolerant to the changing in pH. They kept their viability at pH 3.0 and 4.0.