Project description:Lactobacillus helveticus is a rod-shaped lactic acid bacterium that is widely used in the manufacture of fermented dairy foods and for production of bioactive peptides from milk proteins. Although L. helveticus is commonly associated with milk environments, phylogenetic studies show it is closely related to an intestinal species, Lactobacillus acidophilus, which has been shown to impart probiotic health benefits to humans. This relationship has fueled a prevailing hypothesis that L. helveticus is a highly specialized derivative of L. acidophilus which has adapted to acidified whey. However, L. helveticus has also been sporadically recovered from non-dairy environments, which argues the species may not be as highly specialized as is widely believed. This study employed genome sequence analysis and comparative genome hybridizations to investigate genomic diversity among L. helveticus strains collected from cheese, whey, and whiskey malt, as well as commercial cultures used in manufacture of cheese or bioactive dairy foods. Results revealed considerable variability in gene content between some L. helveticus strains, and indicated the species should not be viewed as a strict dairy-niche specialist. In addition, comparative genomic analyses provided new insight on several industrially and ecologically important attributes of L. helveticus that may facilitate commercial strain selection.
Project description:Lactobacillus helveticus is a rod-shaped lactic acid bacterium that is widely used in the manufacture of fermented dairy foods and for production of bioactive peptides from milk proteins. Although L. helveticus is commonly associated with milk environments, phylogenetic studies show it is closely related to an intestinal species, Lactobacillus acidophilus, which has been shown to impart probiotic health benefits to humans. This relationship has fueled a prevailing hypothesis that L. helveticus is a highly specialized derivative of L. acidophilus which has adapted to acidified whey. However, L. helveticus has also been sporadically recovered from non-dairy environments, which argues the species may not be as highly specialized as is widely believed. This study employed genome sequence analysis and comparative genome hybridizations to investigate genomic diversity among L. helveticus strains collected from cheese, whey, and whiskey malt, as well as commercial cultures used in manufacture of cheese or bioactive dairy foods. Results revealed considerable variability in gene content between some L. helveticus strains, and indicated the species should not be viewed as a strict dairy-niche specialist. In addition, comparative genomic analyses provided new insight on several industrially and ecologically important attributes of L. helveticus that may facilitate commercial strain selection. 42 samples were hybridized to the microarray chip, which contains probe sequences from L. helveticus CNRZ32. CNRZ32 was also hybridized and used as the reference sample. Data from the microarray was statistically analyzed using the R software. Samples were compared to the reference (CNRZ32) to investigate genome diversity amoung L. helveticus strains,
Project description:We performed the long-term administration experiment using a yogurt fermented with Lactobacillus delbrueckii subsp. bulgaricus 2038 and Streptococcus thermophilus 1131 (LB81 yogurt) for 20 months in order to understand the effects of the long-term intake of probiotics on mice. Microarrays were used to compare the gene expressions of the intestine, liver and spleen tissues between control mice and LB81 yogurt-intake mice at 28 months of age. Abbreviations used: A, LB81 yogurt-intake mice; C, control mice
Project description:Fermented dairy milks have been associated with many health benefits including the regulation of metabolic dysfunction. Different circulating clinical biomarkers have been used to explore the effect of fermented milks on metabolic health but the development of whole blood transcriptomics has recently been proposed as a source of novel biomarkers for this health outcome. In a randomised, cross-over study, we evaluate the changes in the whole blood transcriptome after the intake of a probiotic yoghurt compared to a milk acidified with gluconic acid in seven healthy young men. The effects of the dairy foods on whole blood gene expression were assessed at three time points during a 6 h postprandial test (800g single dose) and in the fasting state after a daily intake of the products over two-weeks (400g/d). RNA was extracted from Paxgene ® whole blood samples and sequenced on the Illumina HiSeq platform.
Project description:In this study we conducted a randomized, controlled, cross-over single-meal study
comparing a meal with highly fermented yogurt and cheese, and a meal with beef
and pork meatballs. Postprandial urine samples from 17 subjects were collected
sequentially after each meal up to 24 hr and analyzed by untargeted metabolomics
through an UHPLC-qTOF.