Selection of potential probiotic Lactobacillus strains from human milk

Live microorganisms, have beneficial effects on their host’s health, are called as probiotics. There are various possible sources to isolate these bacteria. The most important criterion is being human origin for human applications. In this study; human milk is used as isolation source because of constructive effects on neonates’ health. It is thought that lactic acid bacteria consisted in breast milk are one of the reason of their beneficial effects. The purpose of this study is to search the human milk according to potential probiotic bacteria and investigate the probiotic properties of isolated lactic acid bacteria.15 different human milk samples were used for isolation of bacteria. Isolates were examined according to their probiotic properties. Low pH resistance, bile salt tolerance and antimicrobial activity assays were chosen for this purpose. Isolates which had these properties were identified biochemically and genetically. Among 60 isolates 2 bacilli showed probiotic properties. These isolates showed resistance to stomach pH (pH 3.0), tolerance against 0.3% bile salt and antimicrobial activity against Salmonella thyphimurium CCM 5445, Escherichia coli O157:H7 NCTC 129000 and Escherichia coli NRRL B-3008. These isolates were biochemically identified and then characterized by using 16S rDNA sequencing. Two lactobacilli, potential probiotic strains, were identified as Lactobacillus oris and Lactobacillus fermentum from human milk origin.