Monoxenic experimental cheese reveals anti-inflammatory effect of Propionibacterium freudenreichii in vivo.
Résumé
Propionibacterium freudenreichii is a beneficial bacterium used as vitamin producer, bio-preservative, cheese ripening starter and probiotic. It adheres to intestinal epithelial cells and mucus and modulates the immune response. Interaction with the host is strain-dependent and relies on key surface proteins, still poorly investigated. We identified surface-exposed proteins in a strain previously selected for its probiotic properties. The role of these proteins in immunomodulatory properties was evidenced. Cheese being a major source of bacteria, we developed an experimental pressed cheese, exclusively fermented by a single strain of P. freudenreichii. Key surface proteins involved in the observed immunomodulatory effects were expressed within the cheese matrix. Consumption of this single-strain cheese protected mice from acute colitis induced by TNBS. P. freudenreichii expressed the key genes of stress tolerance response during growth in the aqueous phase of Emmental cheese, in agreement with enhanced stress tolerance, compared to laboratory culture medium.
This work confirms the probiotic potential of P. freudenreichii, it provides a new functional fermented product for preclinical and clinical studies aimed at prevention or treatment of IBD. It constitutes a basis for further studies aimed at the elucidation of mechanisms responsible for its probiotic effects, in a post-genomic context.