Isolation, Characterization and Determination of Antimicrobial Properties of Lactic Acid Bacteria from Human Milk

Breast milk has a distinctive combination of proteins, carbohydrates, minerals, lipids and various vitamins that promote the proper growth, development and immunity of the infants. That’s why it is considered to be a complete food for new born babies. Moreover, it is also rich in various bioactive compounds which promote the maturation of immune system as well as develop body’s defense against infections. Among these bioactive agents, probiotic bacteria were isolated from human milk in this research work using selective MRS media. Two Lactobacillus spp. were isolated from each of the two breast milk samples, were observed as potential probiotics, and identified using morphological and biochemical tests. These bacteria were facultative anaerobic, gram positive, catalase negative and non-endospore forming. They showed tolerance against 0.3% bile concentration and 1-10% NaCl. Sugar fermentation patterns of both isolated bacteria also greatly varied. Isolate-1 from both sample 1 and 2 showed antimicrobial activity against Shigella flexneri, Shigella dysenteriae, Vibrio cholerae and Salmonella typhi. Isolate-2 from sample 1 and 2 showed antimicrobial activity against Shigella flexneri, Shigella dysenteriae, Vibrio cholerae, Salmonella typhi, Staphylococcus epidermidis and Pseudomonas spp. The addition of breast milk probiotics to infant formulas could be a new alternative to mimic some of the functional effects of human milk in children who are not breastfed