Novel Probiotic Bifidobacterium bifidum CECT 7366 Strain Active against the Pathogenic Bacterium Helicobacter pylori

Abstract

Helicobacter pylori is considered one of the major risk factors underlying the development of gastritis and gastric and duodenal ulcers. Moreover, 50% of the population carries this bacterium, and consequently, when it is detected, eradication of H. pylori is strongly recommended. Regarding the use of probiotics as functional agents, several studies have shown that there is a direct relationship between the addition of certain probiotic bacteria and in vitro inhibition of H. pylori; however, in vivo studies showing bifidobacterial activity against H. pylori remain scarce. In this study, a Bifidobacterium bifidum strain which proved active in vitro against H. pylori has been isolated, with inhibition levels reaching 81.94% in the case of the supernatant and even 94.77% inhibition for supernatant purified by cationic exchange followed by an inverse phase. In vivo studies using a BALB/c mouse model have proved that this strain partially relieves damage to gastric tissues caused by the pathogen and also decreases the H. pylori pathogenicity ratio. This novel strain fulfills the main properties required of a probiotic (resistance to gastrointestinal juices, biliary salts, NaCl, and low pH; adhesion to intestinal mucus; and sensitivity to antibiotics). Furthermore, the absence of undesirable metabolites has been demonstrated, and its food safety status has been confirmed by acute ingestion studies in mice. In summary, the results presented here demonstrate that Bifidobacterium bifidum CECT 7366 can be considered a probiotic able to inhibit H. pylori both in vitro and in vivo.

Novel Probiotic Bifidobacterium longum subsp. infantis CECT 7210 Strain Active against Rotavirus Infections

“…The assay emulated conditions and exposure times to which bacteria are subjected during their passage through the stomach and intestinal tract in two stages and was performed as described previously by Chenoll et al (5). Briefly, bacteria were subjected to simulated gastric and pancreatic juices by using pepsin of pig stomach mucous membrane (3 g/liter; Sigma-Aldrich) and pancreatin of pig pancreas (1 g/liter; Sigma-Aldrich), respectively.…”

“…The resistance levels of the strains to different concentrations of biliary salts (0.5%, 1%, 2%, and 3% [wt/vol] Oxgall; Sigma), NaCl (2%, 3%, 6%, 8%, and 10% [wt/vol] NaCl), and pH (3.0, 2.0, and 1.5) were evaluated by monitoring bacterial growth on 96-well plates according to the methods of Chenoll and coworkers (5). Growth was analyzed at 655 nm in a Multiskan microplate reader (Thermo Fisher Scientific).…”

Comparative Genomics of Bifidobacterium animalis subsp. lactis Reveals a Strict Monophyletic Bifidobacterial Taxon

“…ifidobacteria are intensively exploited by the food industry due to the presumed health beneficial effects they exert on the human host (1)(2)(3)(4)(5). However, the molecular mechanisms underlying these proclaimed health-promoting activities are still largely unknown.…”

Bacteriocin Production: a Probiotic Trait?

“…Indeed, the production of antimicrobials is often regarded a priori as an important trait in the context of bacterial fitness but also in terms of probiotic efficacy. Several probiotic bacteria produce a variety of antimicrobial compounds (e.g., short-chain fatty acids, hydrogen peroxide, nitric oxide, bacteriocins) that may enhance their ability to compete against other GI microbes and which could potentially inhibit pathogenic (disease-causing) bacteria (1,6). Traditionally, bacteriocin production has been an important criterion in the selection of a probiotic strain, albeit that few studies have definitively demonstrated the impact of bacteriocin production on the ability of a strain to compete within the GI tract and/or positively influence the health of the host (9).…”