Muhammah shahid riaz, Tayyaba shaheen, Muhaamad Siddiq, Ahmad Nadeem, Amir Hussain, Fakhar hayyat, Junlin Shi
"Lactic Acid Bacteria (LAB) are the major constituents of the human intestinal micro flora. These have been considered as the major microbial group having probiotic potential. They are able to exert a wide range of beneficial health promoting effects that include inhibition of pathogen growth and production of antimicrobials and vitamins. In food industry, LAB have received considerable attention due to their probiotic activities. The probiotic strain’s ability to resist unfavorable physiological conditions of the gastrointestinal tract (GIT) depends on various factors like tolerance to bile secretion and lysozyme resistance. The present study was conducted with the objectives of in-vitro screening of various indigenous LAB strains isolated from milk and yogurt in order to evaluate their probiotic potential. For probiotic potential, the pH sensitivity, bile resistance, H2O2 and lysozyme resistance of LAB strains will be determined. Our in-vitro studies concluded that PL5 ( Lactobacillus paracasei), PL8 (Enterococcus faecium), PL13 (L. delbrueckii) and PL14 (L. saekei) proved to be most promising LAB strains among all that exhibited a high resistance towards low pH, bile, lysozyme and H2O2. In future, these in-vitro studies will facilitate scientists to select suitable LAB strains and evaluate their probiotic properties in-vivo to understand how they affect human host and cope with adverse conditions in human GI tract. In future, more potential properties of these strains may be checked, like folate & oxalate production, adhesion to mucin, production of β- galactosidase, cholesterol reduction mechanisms on LAB strains. It will be helpful to design new protocols for in-depth studies related to their potentia"