Effect of clinical and probiotic Lactobacillus rhamnosus strains on intestinal permeability and bacterial translocation in healthy and colitic rats

Lactobacillus rhamnosus is one of the most widely used probiotic microorganisms. Although this microorganism is not known for its virulence some rare cases of bacteraemia and endocarditis have been observed. Thus, it is important to identify the possible risks associated with each strain. Comparison of clinical and probiotic strains may give information on properties that could be a safety concern. A possible adverse effect is bacterial translocation. Animals with induced-colitis constitute a good model to assess translocation in the case of mucosal barrier disruption. We aimed at determining the ability of five L. rhamnosus strains, from clinical or probiotic origin, showing different in vitro properties, to induce in vivo translocation in both, healthy and colitic animals. We also tested the effects on the gut mucosal lining by measuring intestinal permeability. None of the in vitro parameters used for selection of the strains included in this study appear to be a risk for translocation or mucosal barrier disruption.