Project description:The survival of probiotics could be strongly enhanced by delivery vehicles, but the mechanism was unknown. In this study, whole genome microarray technology was used to detect the gene expression profiles of probiotic Lactobacillus casei Zhang in the absence and presence of fermented milk in simulated gastrointestinal tract. The results showed the gene expression profiles were significantly different under these two different conditions. The change of the gene expression profile may be helpful to comprehend the role of delivery vehicles in enhancing the survival of probiotics. Twelve samples of bacterial cells in the absence and presence of fermented milk were collected at 3 h in simulated gastric juice, 4 h and 8 h in intestinal juice, 2 biological replicates were obtained in each time point. The average of the normalized expression values of the 2 biological replicates for each probe was regarded as the expression value of a predicted gene. To identify the expression pattern of each gene across different treatments, n-fold change ratios were calculated for every gene in pure L. casei Zhang versus L. casei Zhang in fermented milk.
Project description:Understanding how the human gut microbiota and host are impacted by probiotic bacterial strains requires carefully controlled studies in humans, and in mouse models of the gut ecosystem where potentially confounding variables that are difficult to control in humans can be constrained. Therefore, we characterized the fecal microbiomes and metatranscriptomes of adult female monozygotic twin pairs through repeated sampling 4 weeks prior to, 7 weeks during, and 4 weeks following consumption of a commercially-available fermented milk product (FMP) containing a consortium of Bifidobacterium animalis subsp. lactis, two strains of Lactobacillus delbrueckii subsp. bulgaricus, Lactococcus lactis subsp. cremoris, and Streptococcus thermophilus. In addition, gnotobiotic mice harboring a 15-species model human gut microbiota whose genomes contain 58,399 known or predicted protein-coding genes were studied prior to and after gavage with all five sequenced FMP strains. 140 samples total. Evaluation of changes in a model community's structure over time after exposure to a consortium of 5 fermented milk product (FMP) strains.
Project description:The survival of probiotics could be strongly enhanced by delivery vehicles, but the mechanism was unknown. In this study, whole genome microarray technology was used to detect the gene expression profiles of probiotic Lactobacillus casei Zhang in the absence and presence of fermented milk in simulated gastrointestinal tract. The results showed the gene expression profiles were significantly different under these two different conditions. The change of the gene expression profile may be helpful to comprehend the role of delivery vehicles in enhancing the survival of probiotics.
Project description:We identified the proteins synthesized by Lactobacillus delbrueckii ssp. bulgaricus strain LBB.B5 in laboratory culture medium (MRS) at 37 �C and in milk at 37 and 4 �C. Cell-associated proteins were measured by gel-free, shotgun proteomics using high-performance liquid chromatography coupled with tandem mass spectrophotometry. A total of 635 proteins were recovered from all cultures, and among which 72 proteins were unique to or significantly more abundant in L. bulgaricus after growth in milk compared to MRS at 37 �C.
Project description:Understanding how the human gut microbiota and host are impacted by probiotic bacterial strains requires carefully controlled studies in humans, and in mouse models of the gut ecosystem where potentially confounding variables that are difficult to control in humans can be constrained. Therefore, we characterized the fecal microbiomes and metatranscriptomes of adult female monozygotic twin pairs through repeated sampling 4 weeks prior to, 7 weeks during, and 4 weeks following consumption of a commercially-available fermented milk product (FMP) containing a consortium of Bifidobacterium animalis subsp. lactis, two strains of Lactobacillus delbrueckii subsp. bulgaricus, Lactococcus lactis subsp. cremoris, and Streptococcus thermophilus. In addition, gnotobiotic mice harboring a 15-species model human gut microbiota whose genomes contain 58,399 known or predicted protein-coding genes were studied prior to and after gavage with all five sequenced FMP strains. 73 samples total. Evaluation of changes in a model community's metatranscriptome over time after exposure to a consortium of 5 fermented milk product (FMP) strains (40 samples); evaluation of the gene expression of the FMP strains in other in vitro conditions, including MRS medium (B. animalis subsp. lactis only, 4 samples) and a commercial FMP fermentation (all 5 strains, 6 samples); evaluation of the gene expression of native human microbiomes before and after the consumption of a commercial FMP (23 samples).
Project description:Understanding how the human gut microbiota and host are impacted by probiotic bacterial strains requires carefully controlled studies in humans, and in mouse models of the gut ecosystem where potentially confounding variables that are difficult to control in humans can be constrained. Therefore, we characterized the fecal microbiomes and metatranscriptomes of adult female monozygotic twin pairs through repeated sampling 4 weeks prior to, 7 weeks during, and 4 weeks following consumption of a commercially-available fermented milk product (FMP) containing a consortium of Bifidobacterium animalis subsp. lactis, two strains of Lactobacillus delbrueckii subsp. bulgaricus, Lactococcus lactis subsp. cremoris, and Streptococcus thermophilus. In addition, gnotobiotic mice harboring a 15-species model human gut microbiota whose genomes contain 58,399 known or predicted protein-coding genes were studied prior to and after gavage with all five sequenced FMP strains.
Project description:Understanding how the human gut microbiota and host are impacted by probiotic bacterial strains requires carefully controlled studies in humans, and in mouse models of the gut ecosystem where potentially confounding variables that are difficult to control in humans can be constrained. Therefore, we characterized the fecal microbiomes and metatranscriptomes of adult female monozygotic twin pairs through repeated sampling 4 weeks prior to, 7 weeks during, and 4 weeks following consumption of a commercially-available fermented milk product (FMP) containing a consortium of Bifidobacterium animalis subsp. lactis, two strains of Lactobacillus delbrueckii subsp. bulgaricus, Lactococcus lactis subsp. cremoris, and Streptococcus thermophilus. In addition, gnotobiotic mice harboring a 15-species model human gut microbiota whose genomes contain 58,399 known or predicted protein-coding genes were studied prior to and after gavage with all five sequenced FMP strains.
Project description:The objective of this study was to decipher the metabolism expressed by Lactobacillus delbrueckii subsp. delbrueckii CIRM-BIA865 during soy juice fermentation using transcriptomics. The whole genome was sequenced, assembled and annotated. CIRM-BIA865 was then used to ferment soy juice to produce a soy-based yogurt. Samples were analysed in kinetics during fermentation, at pH values of 6.5, 6, 5 and 4.6. RNA from CIRM-BIA865 were extracted and sequenced using paired-end Illumina. Reads were mapped using Bowtie2 on previously obtained genome of CIRM-BIA865. No mismatch were allowed. Reads mapped on CDS were counted using htseqcount.List of differentially expressed (DE) genes between two successive sampling times (determined by pH) were generated using DEseq2 with a modified t-test and a p-value adjusted by Bonferoni inferior to 0.05. Fold changes expressed how many times genes were induced along the fermentations.