Potential probiotics from human breast milk with promising cholesterol-reduction and anti-tumour effects

Abstract

Background and rationale: The objective of this study is to isolate probiotic bacteria from human breast milk and test their health benefits as cholesterol reduction and human DNA protection. Methods: Potential probiotic bacteria were isolated from human milk. The probiotic properties were tested namely their ability to survive acidic pH, tolerate bile salts and antimicrobial activities. Serum cholesterol reduction ability and cytoprotective effect on Hep-2 cells were studied. Results: A total of 48 different isolates were purified from 12 breast milk samples. They all tolerated bile salts while 81% were proved to be resistant to acidic pH and had antimicrobial effects against different pathogens. Three isolates showed high ability to reduce cholesterol from 19.4-22.6%. This percentage of cholesterol reduction was improved in presence of bile salt to be 48.7-54.7%. Four isolates were proved to have a protective effect against the H2O2 cytotoxicity by decreasing tail moment up to 2.8 and 15.6% DNA concentration in the tail of the examined cells. Phenotypic characteristics and 16S rDNA sequence analyses were used to identify the promising isolates as Pediococcus pentosaceus, Enterococcus durans, and Enterococcus faecium strains. Conclusion: Probiotic strains isolated from human milk in the study had a dual beneficial role; human health benefit as well as cytoprotective activities.