Three New Lactobacillus plantarum Strains in the Probiotic Toolbox against Gut Pathogen Salmonella enterica Serotype Typhimurium

Abstract

The benefits of probiotic bacteria have been widely explored. However, fermented foods and digestive system of humans and animals are an inexhaustible source of new potentially probiotic microorganisms. In this study we present three new <i>Lactobacillus plantarum</i> strains isolated from different dairy products: cow's cheese, sheep's cheese and whey. In order to determine the antibacterial activity of yet unexplored <i>L. plantarum</i> strains against <i>Salmonella enterica</i> serotype Typhimurium, <i>in vitro</i> competition and co-culture tests were done. Furthermore, adhesion of these strains to Caco-2 cells and their influence on the adhesion of <i>Salmonella</i> were tested. Results showed the potential probiotic activity of isolated strains. <i>L. plantarum</i> strains survived in the presence of 1% bile salts, they possessed acidification ability, antibacterial activity and significantly attenuated the growth of <i>S.</i> Typhimurium in brain heart infusion broth. All tested <i>L. plantarum</i> strains were able to adhere to Caco-2 cells and significantly impair the adhesion of <i>S.</i> Typhimurium. All three <i>L. plantarum</i> strains exhibited significant probiotic potential and anti-<i>Salmonella</i> activity; therefore, further testing on <i>in vivo</i> models should follow.