IN VITRO AND IN VIVO INVESTIGATION OF PROBIOTICS ISOLATED FROM HUMAN MILK

Abstract

People all over the world are embracing probiotics as a result of growing awareness of the health advantages connected to ingesting living bacteria. Proper administration of probiotics has been shown to provide numerous health advantages to the host. The Lactobacillus genus, which naturally resides in the mucosal linings of humans and animals, and it is essential for stabilizing the gastrointestinal tract and protecting intestinal health from infections. There has been a great deal of interest in their potential uses as probiotics, mucosal vaccine vectors, and agents regulating metabolic activities. The present study aimed at isolating and characterizing novel probiotics from human milk and functionally assessing them in vivo for their physiological, enzymatic and antimicrobial activity. Probiotic isolates from human milk were amylolytic, proteolytic and lipolytic and were found to be tolerant to low pH of 3.5, 10% salt and 0.3% bile salt. Primary method of cross streaking and secondary streaking by agar diffusion method revealed antagonistic activity of the isolates against tests pathogens of humans viz., S. aureus Newman, P. fluorescens, S. epidermis and S. aureus. Antibiofilm activity of probiotic isolates in vivo against P. fluorescens and S. aureus Newman indicated that the metabolites present in the Cell Free Supernatant (CFS) of the isolates may have the ability to inhibit the formation of biofilm of pathogenic strains. The most efficient probiotic isolates was identified as Weissella confusa and the NCBI GenBank accession number was obtained. The infected mice administered with probiotic isolate Weissella confusa PS17 showed reduced mortality rate than the mice infected with pathogenic strain S. aureus Newman, thus indicating that probiotic strain boosted the immune response of the mice. The Serum uric acid levels was normalised after the infected mice was treated with W. confusa PS17 and this in turn enhanced the survival rate of mice. The present study indicates that isolate W. confusa PS17 can be a promising candidate in improving the condition of health.