title: Comparative genomic and functional analysis of Lactobacillus casei and Lactobacillus rhamnosus strains marketed as probiotics.
abstract: Four Lactobacillus strains were isolated from marketed probiotic products, including L. rhamnosus strains from Vifit (Friesland Campina) and Idoform (Ferrosan) and L. casei strains from Actimel (Danone) and Yakult (Yakult Honsa Co.). Their genomes and phenotypes were characterized and compared in detail with L. casei strain BL23 and L. rhamnosus strain GG. Phenotypic analysis of the new isolates indicated differences in carbohydrate utilization between L. casei and L. rhamnosus strains, which could be linked to their genotypes. The two isolated L. rhamnosus strains had genomes that were virtually identical to that of L. rhamnosus GG, testifying to their genomic stability and integrity in food products. The L. casei strains showed much greater genomic heterogeneity. Remarkably, all strains contained an intact spaCBA pilus gene cluster. However, only the L. rhamnosus strains produced mucus-binding SpaCBA pili under the conditions tested. Transcription initiation mapping demonstrated that the insertion of an iso-IS30 element upstream of the pilus gene cluster in L. rhamnosus strains but absent in L. casei strains had constituted a functional promoter driving pilus gene expression. All L. rhamnosus strains triggered an NF-κB response via Toll-like receptor 2 (TLR2) in a reporter cell line, whereas the L. casei strains did not or did so to a much lesser extent. This study demonstrates that the two L. rhamnosus strains isolated from probiotic products are virtually identical to L. rhamnosus GG and further highlights the differences between these and L. casei strains widely marketed as probiotics, in terms of genome content, mucus-binding and metabolic capacities, and host signaling capabilities.
authors: Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland.
authors: François P
authors: FP
authors: Douillard
authors: Angela
authors: A
authors: Ribbera
authors: Hanna M
authors: HM
authors: Järvinen
authors: Ravi
authors: R
authors: Kant
authors: Taija E
authors: TE
authors: Pietilä
authors: Cinzia
authors: C
authors: Randazzo
authors: Lars
authors: L
authors: Paulin
authors: Pia K
authors: PK
authors: Laine
authors: Cinzia
authors: C
authors: Caggia
authors: Ingemar
authors: I
authors: von Ossowski
authors: Justus
authors: J
authors: Reunanen
authors: Reetta
authors: R
authors: Satokari
authors: Seppo
authors: S
authors: Salminen
authors: Airi
authors: A
authors: Palva
authors: Willem M
authors: WM
authors: de Vos
mesh_terms: D015373:Bacterial Typing Techniques; D014644:Genetic Variation; D005838:Genotype; D007780:Lacticaseibacillus casei / Q000235:genetics* / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D052201:Lacticaseibacillus rhamnosus / Q000235:genetics* / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D010641:Phenotype; D019936:Probiotics