Antibacterial effect of the adhering human Lactobacillus acidophilus strain LB

Abstract

The spent culture supernatant of the human Lactobacillus acidophilus strain LB produces an antibacterial activity against a wide range of gram-negative and gram-positive pathogens. It decreased the in vitro viability of Staphylococcus aureus, Listeria monocytogenes, Salmonella typhimurium, Shigella flexneri, Escherichia coli, Klebsiella pneumoniae, Bacillus cereus, Pseudomonas aeruginosa, and Enterobacter spp. In contrast, it did not inhibit lactobacilli and bifidobacteria. The activity was heat stable and relatively sensitive to enzymatic treatments and developed under acidic conditions. The antimicrobial activity was independent of lactic acid production. Activity against S. typhimurium SL1344 infecting human cultured intestinal Caco-2 cells was observed as it was in the conventional C3H/He/oujco mouse model with S. typhimurium C5 infection and oral treatment with the LB spent culture supernatant.

Probiotics in infectious diarrhoea in children: are they indicated?

“…Since some commercialized products are combinations of different strains, repeated laboratory and clinical testing of every combination of strains is mandatory. Lactobacillus acidophilus LB has been shown to have antibacterial activity against E. coli [4,15]. However, if the E. coli is present in the gastro-intestinal tract of the host prior to the L. acidophilus LB, as occurs in acute gastroenteritis, its antibacterial activity is strongly reduced by non-specific steric hindrance of the receptor sites [41].…”

Metabolites of Lactobacillus plantarum 2142 Prevent Oxidative Stress-Induced Overexpression of Proinflammatory Cytokines in IPEC-J2 Cell Line

“…Several antibacterial molecules other than bacteriocins, organic acids and hydrogen-peroxide have been found to be derived from lactobacilli, but the structural characterization has not been performed yet. L. acidophilus LB and Lactobacillus johnsonii LA1 produced a heat-stable substance resistant to protease [37,38].…”

Probiotic microorganisms: how they affect intestinal pathophysiology

“…at the terminal ileum level [102]. The adherence of certain strains of Lactobacillus to the intestinal epithelial cells, which is a criterion of selection for probiotic strains, can significantly inhibit the binding of enteric pathogens, by competitive exclusion, as shown at least in vitro [53,103,104]. This inhibition of adhesion of enteropathogens could be due in part to the induction of intestinal mucin gene expression [105] and to the ability of probiotic bacteria to bind to human intestinal mucus [106,107] and to human colonic cell lines [104,108,109].…”

“…This biotherapeutics is often used as an adjunct to the traditional anti-biotherapy and clinical trials seem to confirm the improvement of eradication rate and the tolerability of multiple antibiotic regimens used for the infection. L. acidophilus strain LB secreting an anti-bacterial substance against H. pylori in vitro and in vivo was reported to decrease the adhesion and viability of H. felis in mice and of H. pylori in the cultured human mucosecreting HT29-MTX intestinal cell line [53].…”