COMPARATIVE GENOMIC ANALYSIS OF THE MULTISPECIES PROBIOTIC MARKETED PRODUCT
François P. Douillard, Research Program Unit Immunobiology, Medicum, University of Helsinki, Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki – Diego Mora, Department of Food, Environmental, and Nutritional Sciences (DeFENS), University of Milan – Robyn T. Eijlander and Michiel Wels, NIZO, Ede, The Netherlands Research Program Unit Immunobiology, Medicum, University of Helsinki – Willem M. de Vos, Research Program Unit Immunobiology, Medicum, University of Helsinki, Laboratory of Microbiology, Wageningen University.
In this work, the genomes of all eight bacterial strains present in VSL#3 were sequenced and characterized, to advance insights into the possible mode of action of this product and also to serve as a basis for future work and trials. Phylogenetic and genomic data analysis allowed us to identify the 7 species present in the VSL#3 product as specified by the manufacturer. The 8 strains present belong to the species Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus paracasei, Lactobacillus plantarum, Lactobacillus helveticus, Bifidobacterium breve and B. animalis subsp. Lactis (two distinct strains). Comparative genomics revealed that the draft genomes of the S. thermophilus and L. helveticus strains were predicted to encode most of the defence systems such as restriction modification and CRISPR-Cas systems. Genes associated with a variety of potential probiotic functions were also identified. Thus, in the three Bifidobacterium spp., gene clusters were predicted to encode tight adherence pili, known to promote bacteria-host interaction and intestinal barrier integrity, and to impact host cell development. Various repertoires of putative signalling proteins were predicted to be encoded by the genomes of the Lactobacillus spp., i.e. surface layer proteins, LPXTG-containing proteins, or sortasedependent pili that may interact with the intestinal mucosa and dendritic cells.
Taken altogether, the individual genomic characterization of the strains present in the VSL#3 product confirmed the product specifications, determined its coding capacity as well as identified potential probiotic functions.
Read the full article: http://journals.plos.org/plosone/article/authors?id=10.1371/journal.pone.0192452