Abstract

Introduction

Recently, much attention has been paid to the health promoting properties of lactobacilli and bifidobacteria. Probiotics and prebiotics are the driving forces of the functional foods market. However, a major problem is that many of these health-promoting properties are still questioned. For instance, the fundamental basis of the inhibition of Gram negative pathogenic bacteria - such as the enterovirulent diarrheagenic Salmonella and Helicobacter pylori causing gastrointestinal disorders - by probiotic lactic acid bacteria has not been elucidated. This project will focus on the identification of the responsible compounds. In addition, the mechanism of the inhibition of Gram-negative pathogens by probiotic lactobacilli and bifidobacteria will be studied using coculture models (simulated gut fermentations. human cell lines, and animal models). Clinical studies will also be carried out.

Objectives

• to obtain a selection of probiotic lactobacilli and bifidobacteria that display a clear inhibition of diarrheagenic Gram-negative pathogenic bacteria and Helicobacter pylori.
• to identify the metabolite(s) responsible for the inhibition and/or killing of Gram-negative pathogenic bacteria;
• to have the conditions and kinetics elucidated of the production of antimicrobials active towards Gram-negative pathogens and to predict their in vivo action:
• to establish co-culture models (simulated gut fermentations. human cell lines, animal models) to study the interaction between inhibitory lactic acid bacterial strains and Gram-negative pathogens causing gastrointestinal disorders:
• to have the selected probiotic lactic acid bacterium strains tested in clinical studies.

Results and Achievements

• A project culture collection of probiotic lactobacilli and bifidobacteria strains together with characteristic data and inhibitory spectrum
• A molecular typing method for selected probiotic strains
• Identified compound(s) responsible for the inhibition of Gram-negative pathogenic bacteria
• The conditions of antimicrobial production in the gut environment
• Co-culture models (simulated gut fermentations, human cell line cultures. animal models) showing the inhibitory action by the probiotic strains.

Contacts

Coordinator

• Luc De VUYST / Vrije Universiteit Brussel Research Group of Industrial Microbiology, Fermentation / BELGIUM

Participant

• Agricultural University of Norway Department of Chemistry and Biotechnology / NORWAY
• Thierry DAUVRIN / Beldem S.A. R & D Laboratory / BELGIUM
• Lorand SAVU / Dexter Com Srl ROMANIA
• Andreas MENTIS / Hellenic Pasteur Institute Laboratory of Bacteriology / GREECE
• Alain SERVIN / Institut Nalional de Ia Sante et de Ia Recherche Medicale INSERM Unite 510 / FRANCE