Lactobacilli from Fermented Portuguese Table-Olives Are Able to Inhibit the Human Pathogen Helicobacter pylori

摘要

Probiotic bacteria are a safe source of microbial metabolites, which may constitute a future alternative to antibiotic therapy, as acquired resistances are spreading among bacteria from a growing number of genera and habitats. Helicobacter pylori (HP) is such an example of a human pathogen in which multiple resistances to antibiotics are commonly found. The current study deals with the screening of anti-Helicobacter pylori (anti-HP) activity among Lactic Acid Bacteria (LAB) isolated from fermented table-olives. Firstly, the aptitude of these 14 LAB strains (all bacteriocin producers from genus Lactobacillus) was evaluated regarding their use as probiotics. Besides their GRAS (Generally Recognized As Safe) Status, all of them showed to withstand "in vitro" tests for the simulation of the digestion and displayed high levels of bile tolerance. Several HP strains were inhibited by LAB's diffusible metabolites, others than lactate. The inhibitory responses against HP were strain-specific and independent of their antibiotic susceptibility pattern. The identification of potential probiotic bacteria from Portuguese table-olives is a relevant aspect for the valorisation of the Mediterranean diet, and it opens the way for the classification of fermented table-olives as functional foods.