Throughout the history of microbiology, most human studies have been focused on the disease-causing organisms found on or in people; whilst fewer studies have examined the benefits of the bacteria. However, we are surrounded by beneficial microorganisms that live in or on the human body. Probiotics are defined as live microorganisms when administered in adequate amounts confer a health benefit on the host1–2. Lactic acid bacteria (LAB) are considered as [Generally Recognized as Safe (GRAS)] organisms and can be safely used as probiotics for medical applications3. Members of the genus Lactobacillus are the most common probiotics used in commercial fermented and non-fermented products, such as in some yogurts and fermented milk drinks, as well as dietary supplements, which are available in the market in the form of capsules, liquid/gel, and powdered, to combat the diseases due to their ability to inhibit the pathogenic microorganisms4. Lactobacilli, primarily facultative or strict anaerobes generally have fastidious growth requirements. They prefer an acidic environment by producing lactic and other acids. In general, Lactobacilli have not been associated with disease and have been regarded as non-pathogenic and isolates were able to tolerate the acidic condition of the environment, NaCl concentration, and resistance to bile. The reported health benefits of probiotics include: boosting of the immune system, inhibition of the growth of pathogenic organisms, prevention of diarrhea from various causes, improvement of digestion of proteins and fats and synthesis of vitamins5. This study was conducted to detect the antimicrobial activity of the probiotic lactobacilli isolated from a commercial probiotic product against some bacterial pathogens. Probiotics, a word derived from Latin, that means ’for life’, have been with us for as long as people have eaten fermented milk, but their association with health benefits dates only from the turn of the last century. Growing awareness of the health benefits of consuming microorganisms such as probiotics have encouraged consumers worldwide. These probiotic bacteria are essential for their beneficial effect on a particular organism’s health and host nutrition for healthy gastrointestinal function. The original modern hypothesis of the positive role played by certain bacteria was first introduced by Russian scientist Élie Metchnikoff, who in 1907 suggested that it would be possible to modify the gut microbiota and replace harmful microbes with useful microbes6. On the other hand, the rise in antibiotic antibiotic-resistant has awakened the scientific community to the prophylactic and therapeutic uses of probiotics and to reconsider them as alternatives to antibiotics7. Over the last years, there has been increasing public and scientific interest in the administration of these live micro-organisms to prevent or treat disease. Twenty-three publications were retrieved from PubMed for the year 1995 using the search term ‘probiotic’ compared with about 200 in the year 2000 and more than 600 for the first half of 2012. Much of the focus of this research has been on the use of probiotics for the prevention or treatment of gastrointestinal conditions such as inflammatory bowel disease and inflammatory bowel syndrome8 Antimicrobial activity of Lactobacillus strains against bacterial pathogens emerges to be multifactorial and includes the production of hydrogen peroxide, lactic acid, bacteriocin-like molecules, and unknown heat-stable, non-lactic acid molecules9. Other mechanisms proposed for their activity are competition for nutrients10–11, adhesion inhibition of pathogens to the surface, and stimulation of the immune system12.One of the important features of probiotic lactobacilli to achieve antagonistic activity against bacterial pathogens because of their capacity to produce lactic acid and other organic acids that lower the pH in the human intestine, and to produce H2O2 and bacteriocin, thereby establishing a hospital environment for the growth and survival of various human pathogenic bacteria. There are also other physiological benefits of probiotics that have been published as it helps in the removal of carcinogens, lowering of cholesterol, immune-stimulating and allergy lowering effect, synthesis and enhancing the bioavailability of nutrients, alleviation of lactose intolerance13. One important limitation is that only one kind of probiotic bacteria may not exert protection against all harmful strains that cause gastrointestinal pathogenic infections14.