en Medical Biology Medical Biology مقاله پژوهشی Original Research Article <p style="text-align: justify;"><span style="font-size:16px;"><span style="font-family:Times New Roman;"><strong new="" roman="" style="font-family: " times=""><span style="color:#ffffff;"><span style="background-color:#16a085;">Background and Objective:</span></span>&nbsp;</strong><span style="line-height:150%"><span style="line-height:150%">Breast milk contains nutrients such as carbohydrates, essential fatty acids, proteins, vitamins, minerals, and a source of communal bacteria with probiotic potential that is very effective in the prevention and treatment of neonatal infections. The aim of this study was the evaluation of probiotic properties of lactobacilli in breast milk and their inhibitory effect on pathogenic bacteria of the gastrointestinal tracts.</span></span><br> <strong new="" roman="" style="font-family: " times=""><span style="color:#ffffff;"><span style="background-color:#16a085;">Materials and Methods:</span></span>&nbsp;</strong><span style="line-height:150%"><span style="line-height:150%">In a cross-sectional descriptive study, during 10 months</span> <span style="line-height:150%">from January to October 2018, 100 breast milk samples were collected by referring to health centers after isolation. Lactobacilli strains were evaluated based on morphological characteristics, catalase, and hot staining tests, survival tests in acidic conditions, and bile salt tolerance to evaluate probiotic properties. Antibiotic resistance of probiotic strains and ability to inhibit pathogenic bacteria was evaluated by well method and growth inhibition zone.</span></span><br> <strong new="" roman="" style="font-family: " times=""><span style="color:#ffffff;"><span style="background-color:#16a085;">Results:</span></span></strong>&nbsp;<span style="line-height:150%"><span style="line-height:150%">122 lactobacilli belonging to 12 species were identified from 100 samples of breast milk by phototypical methods. The predominant species belonging to casei and other lactobacilli were Fermentum, Plantarum, and Gasseri, respectively.The highest antibiotic resistance was related to vancomycin (63.15%). The 3 isolates L4, L14 and L16 were able to strongly inhibit all the studied gastrointestinal pathogens.</span></span><br> <strong new="" roman="" style="font-family: " times=""><span style="color:#ffffff;"><span style="background-color:#16a085;">Conclusion:</span></span>&nbsp;</strong><span style="line-height:150%"><span style="line-height:150%">Breast milk is a rich source of beneficial probiotic lactobacilli, which can be useful in breast milk for infants who are not breastfed to prevent neonatal infections.</span></span></span></span></p> Breast milk, Lactobacillus, Probiotic, Inhibitory effect 536 543 http://journal.zums.ac.ir/browse.php?a_code=A-10-460-4&slc_lang=en&sid=1 Mohammad Mehdi Soltan-Dallal msoltandallal@gmail.com 5200319475328460073688 5200319475328460073688 No Dept. of Food Microbiology, School of Health, Tehran University of Medical Sciences, Tehran, Iran Zahra Rajabi z_rajabi.arshad@yahoo.com 5200319475328460073689 5200319475328460073689 No Food Microbiology Research Center, Tehran University of Medical Sciences, Tehran, Iran Sara Sharifi Yazdi mksharifiyazdi@gmail.com 5200319475328460073690 5200319475328460073690 Yes School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Parisa Torabi-Bonab parisatorabi.mic19@yahoo.com 5200319475328460073691 5200319475328460073691 No Food Microbiology Research Center, Tehran University of Medical Sciences, Tehran, Iran Alireza Monadi Sefidan Arms.monadi@gmail.com 5200319475328460073692 5200319475328460073692 No Dept. of Medical Laboratory Sciences, Faculty of Allied Medical Sciences, Tehran University of Medical Sciences, Tehran, Iran Sina Sharifi Yazdi sinasharifiyazi@gmail.com 5200319475328460073693 5200319475328460073693 No School of Medicine, Tehran University of Medical Sciences, Tehran, Iran