Starter SURFace against INFlammation of the Gut: Role of Lactobacillus delbrueckii and Propionibacterium freudenreichii surface proteins in the modulation of gut inflammation

Informations

Funding country

France

Acronym

SURFING : Starter SURFace against INFlammation of the Gut

URL

-

Start date

1/1/2011

End date

-

Budget

587,381 EUR

Fundings

Abstract

Inflammatory bowel diseases (IBD) constitute a main health concern in industrialized countries. Their incidence is currently about 1% of the population in these countries. In addition to some genetic predisposition, they are linked to lifestyle and diet. They are caused by a disregulation of the immune system leading to disequilibrium between protection towards pathogens and tolerance towards gut commensal bacteria. Intestinal inflammation, key factor in IBD, can be partly treated by consumption of bacterial strains selected for their immunomodulatory and anti-inflammatory properties. In this context, the effect of some bacteria commercialized in this aim, mainly belonging to the genus Bifidobacterium or Lactobacillus, was thoroughly studied. Propionibacterium freudenreichii (Pf) and Lactobacillus delbrueckii (Ld) are two bacterial species massively used as starters in fermented dairy products. Despite this massive use, the anti-inflammatory potential of these two species is surprisingly rarely studied. Pf is massively ingested via the consumption of Swiss type cheeses and of a growing number of other cheeses in which this starter is more and more used to improve organoleptic properties. Ld is very abundant in various fermented dairy products. The subspecies lactis is more and more used in Swiss type cheeses because of its acidifying abilities. As an example, one gram of Emmental cheese contains 108 to 109 cells of Pf and 103 to 109 cells of Ld, which are potentially immunomodulatory. The Ld subspecies bulgaricus is also highly consumed in various fermented milks, including yogurt. In the SURFING project, we will focus on the immunomodulatory properties of these two dairy starters. Indeed, cheeses and fermented milks already on the market contain high amounts of Pf and Ld. These two bacteria can thus help in treating IBD, via specific surface components showing variable anti-inflammatory properties which are crucial and should be characterized. Our preliminary results revealed anti-inflammatory properties which are highly strain-dependent in both Pf and Ld. One selected strain of each species was tested in an experimental model of colitis in mice and revealed a promising protective effect. The aims of the SURFING project are: 1- Show that the ingestion of Pf or of Ld can have an anti-inflammatory impact in the context of IBD. 2- Identify the surface proteins responsible for the two species immunomodulatory properties 3- Elucidate the molecular mechanisms of the immune response triggered in vitro and in vivo in epithelial cells 4- Confirm the presence of the key surface immunomodulatory proteins in real conditions during starter preparation and dairy products making using these Pf and Ld starters.