This study was aimed to determine how much probiotic-LAB strains belonging to L. kefiranofaciens, L. parakefiri and L. kefiri species species found in natural kefir-grain were transferred to the feces of experimental-animals and how long they colonized to intestinal-systems of experimental animals. A total of 30 male Balb/c mice were fed with the kefir-drink produced using kefir-grain. Feces samples, collected during 15 days, were analyzed by qPCR. As a result, it was determined that the transfer of the L. kefiranofaciens, the L. kefiri, and especially the L. parakefiri strains, which specific to natural-kefir, produced using kefir-grain, into mice feces microbiota was determined for the first time. In the intestinal-microbiota of the mice, the L. kefiranofaciens strain had higher colonization efficiencies than others. Besides, the L. parakefiri strain with the highest amount of increase supported the mice-feces-microbiota. Thus, the efficacy of natural-kefir in transferring tested probiotic strains to the mice-feces was proven.