Department of Microbiology, Faculty of Pharmacy, University of Granada, 18071 Granada, Spain.
Department of Nutrition and Bromatology, Faculty of Pharmacy, University of Granada, 18071 Granada, Spain.
Res Microbiol. 2014 Jan;165(1):14-20. doi: 10.1016/j.resmic.2013.10.006. Epub 2013 Oct 17.
Increased resistance to infection is one of the beneficial effects attributed to probiotic microorganisms. This effect may be due to several mechanisms: production of inhibitory substances, blocking of adhesion sites on the intestinal surface, competition for nutrients and stimulation of mucosal and systemic immunity. The present study aimed to investigate the correlation between in vitro and in vivo antimicrobial activity of probiotic lactobacilli. The agar spot test was used to show that twenty Lactobacillus strains were able to inhibit the enteropathogenic bacterium Yersinia enterocolitica. This inhibition was mainly attributable to a decrease in pH resulting from dextrose fermentation by lactobacilli. The inhibition of Y. enterocolitica, Salmonella enterica serovar Typhimurium and Listeria monocytogenes by two probiotic strains, Lactobacillus casei C1 and Lactobacillus plantarum C4, was also associated with the pH decrease. However, both strains lacked protective effects in mouse experimental infection models, with the exception of long-lasting pre-treatment with L. plantarum C4, which exerted a partial protective effect against S. Typhimurium that was attributable to an immunostimulatory mechanism. Our results show that in vitro antibiosis tests do not provide useful information on the probiotic potential of Lactobacillus strains.
增强抗感染能力是益生菌微生物的有益作用之一。这种作用可能是由于几种机制：产生抑制物质、阻断肠道表面的粘附位点、竞争营养物质和刺激黏膜和全身免疫。本研究旨在研究益生菌乳杆菌的体外和体内抗菌活性之间的相关性。琼脂点试验表明，二十株乳杆菌能够抑制肠道致病菌耶尔森氏菌。这种抑制主要归因于乳杆菌通过发酵葡萄糖导致 pH 值下降。两种益生菌菌株——干酪乳杆菌 C1 和植物乳杆菌 C4 对肠炎沙门氏菌 Typhimurium 和李斯特菌的抑制作用也与 pH 值下降有关。然而，除了植物乳杆菌 C4 的长期预处理外，这两种菌株在小鼠实验感染模型中均没有保护作用，而植物乳杆菌 C4 的预处理对肠炎沙门氏菌具有部分保护作用，这归因于免疫刺激机制。我们的结果表明，体外抑菌试验不能为乳杆菌菌株的益生菌潜力提供有用信息。
