Research Article Probiotic Potential of Lactobacillus Strains with Antimicrobial Activity against Some Human Pathogenic Strains Parisa Shokryazdan, 1 Chin Chin Sieo, 1,2 Ramasamy Kalavathy, 3 Juan Boo Liang, 4 Noorjahan Banu Alitheen, 2 Mohammad Faseleh Jahromi, 4 and Yin Wan Ho 1 1 Institute of Bioscience, Universiti Putra Malaysia (UPM), 43400 Serdang, Selangor, Malaysia 2 Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia (UPM), 43400 Serdang, Selangor, Malaysia 3 Faculty of Pharmacy, Universiti Teknologi MARA, 42300 Puncak Alam, Selangor, Malaysia 4 Institute of Tropical Agriculture, Universiti Putra Malaysia (UPM), 43400 Serdang, Selangor, Malaysia Correspondence should be addressed to Yin Wan Ho; ywho@upm.edu.my Received 12 April 2014; Revised 10 June 2014; Accepted 10 June 2014; Published 3 July 2014 Academic Editor: Frederick D. Quinn Copyright © 2014 Parisa Shokryazdan et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Te objective of this study was to isolate, identify, and characterize some lactic acid bacterial strains from human milk, infant feces, and fermented grapes and dates, as potential probiotics with antimicrobial activity against some human pathogenic strains. One hundred and forty bacterial strains were isolated and, afer initial identifcation and a preliminary screening for acid and bile tolerance, nine of the best isolates were selected and further identifed using 16 S rRNA gene sequences. Te nine selected isolates were then characterized in vitro for their probiotic characteristics and their antimicrobial activities against some human pathogens. Results showed that all nine isolates belonged to the genus Lactobacillus. Tey were able to tolerate pH 3 for 3h, 0.3% bile salts for 4 h, and 1.9 mg/mL pancreatic enzymes for 3 h. Tey exhibited good ability to attach to intestinal epithelial cells and were not resistant to the tested antibiotics. Tey also showed good antimicrobial activities against the tested pathogenic strains of humans, and most of them exhibited stronger antimicrobial activity than the reference strain L. casei Shirota. Tus, the nine Lactobacillus strains could be considered as potential antimicrobial probiotic strains against human pathogens and should be further studied for their human health benefts. 1. Introduction Probiotics are defned as “live microorganisms which when administered in adequate amounts confer a health bene- ft on the host” [1]. During the last decade, the use of probiotics for human has received increasing attention as scientifc evidence continues to accumulate on the properties, functionality, and benefcial efects of probiotic bacteria on humans. Te search for more new probiotics is driven by the growing demand for probiotic functional food and beverages and dietary supplements due to rising levels of health con- sciousness and growing consumer awareness regarding gut health and the concept of preventive health care. It is now well established that some of the infections and disorders in the human body, such as irritable bowel syndrome, infammatory bowel disease, and antibiotic-induced diarrhea, could be due to defcient or compromised intestinal microfora, and probiotics have been considered to be one of the disease control strategies to overcome such disorders [2]. Tus, probiotics have become increasingly considered for use in the food industry. Lactic acid bacteria, especially Lactobacillus, are the most commonly used microorganisms as probiotics because of the perception that they are desirable members of the intestinal microfora and because these bacteria have “Generally Recognized As Safe” (GRAS) status. Te growing interest in probiotics has resulted in many purported probi- otic products being marketed without adequate studies on the probiotic properties of the strains leading to problems of inconsistent efcacy of the products. Since the properties of probiotic are strain-specifc, the quality of products is closely linked to the individual strains in the products. Tus, they should be correctly identifed, and their probiotic Hindawi Publishing Corporation BioMed Research International Volume 2014, Article ID 927268, 16 pages http://dx.doi.org/10.1155/2014/927268