Project description:Although intestinal microbiota play a pivotal role in the development of host immune system this biological issue was not so far studied in great detail. In this study we examined immune response of Caco-2 enterocytes after incubation with common probiotic Bifidobacterium animalis subsp. lactis BB-12 for 4 hours. We used microarrays to inspect the global gene expression of Caco-2 cells upon co-culturing with B. animalis subsp. lactis BB-12 and several distinct immune-related genes up-regulated during this process. One time point (T4) and two controls (T0) were analysed. T0 represent differentiated Caco-2 cells cultivated for 3 weeks. T4 represents differentiated Caco-2 cells cultivated for 3 weeks plus consequent 4 hours of co-cultivation with B. animalis subsp. lactis BB-12. 3 technical replicates for T0-1, T0-2 or T4 were pooled to a single sample, RNA extracted and further used in gene expression experiments.
Project description:Although intestinal microbiota play a pivotal role in the development of host immune system this biological issue was not so far studied in great detail. In this study we examined immune response of Caco-2 enterocytes after incubation with common probiotic Bifidobacterium animalis subsp. lactis BB-12 for 4 hours. We used microarrays to inspect the global gene expression of Caco-2 cells upon co-culturing with B. animalis subsp. lactis BB-12 and several distinct immune-related genes up-regulated during this process.
Project description:Bifidobacterium animalis subsp. lactis BB12 is a widely used probiotic bacterium. However the molecular mechanism by which this bacterium confers positive health effects to the host is largely unknown. The importance of lipoteichoic acids (LTA) in the cross-talk between the bacteria and human enterocyte-like Caco-2 cells was investigated in the present study. A microarray-based analysis of gene expression revealed induction of genes encoding enzymes involved in the synthesis of lipoteichoic acids of BB12. This observation was confirmed in phenotypic experiments, where a specific galactofuranosyl carbohydrate epitope present in the structure of lipoteichoic acids of BB12 was used as a detection marker. An exopolysaccharide EPS/LTA extract isolated from BB12 and commercially available pure LTAs from the human pathogen S. pyogenes were tested in competitive adhesion experiments. The adhesion of B. animalis subsp. lactis BB12 to Caco-2 cells was inhibited in presence of LTA. The strongest inhibition was observed in the concentration range 0.5-10 ug/ml for LTAs from S. pyogenes and 5-10 ug/ml for EPS/LTA extract from BB12. The inhibitory concentrations in both cases likely reflect the physico-chemical properties of LTAs with the highest efficacy below the critical micelle concentration, and therefore we ascribe the main inhibitory effect to LTAs for the BB12 isolated EPS/LTA extract as well. In conclusion we present increased biosynthesis of lipoteichoic acids of BB12 co-incubated with human Caco-2 cells and evidence that LTA serve as important cell wall factors involved in adhesion to these human enterocyte-like cells. The experimental design is described under the single sample. Data desribed in the manuscript (as briefly described under Summary/Abstract) were validated by qPCR.
Project description:Bifidobacterium animalis subsp. lactis BB12 is a widely used probiotic bacterium. However the molecular mechanism by which this bacterium confers positive health effects to the host is largely unknown. The importance of lipoteichoic acids (LTA) in the cross-talk between the bacteria and human enterocyte-like Caco-2 cells was investigated in the present study. A microarray-based analysis of gene expression revealed induction of genes encoding enzymes involved in the synthesis of lipoteichoic acids of BB12. This observation was confirmed in phenotypic experiments, where a specific galactofuranosyl carbohydrate epitope present in the structure of lipoteichoic acids of BB12 was used as a detection marker. An exopolysaccharide EPS/LTA extract isolated from BB12 and commercially available pure LTAs from the human pathogen S. pyogenes were tested in competitive adhesion experiments. The adhesion of B. animalis subsp. lactis BB12 to Caco-2 cells was inhibited in presence of LTA. The strongest inhibition was observed in the concentration range 0.5-10 ug/ml for LTAs from S. pyogenes and 5-10 ug/ml for EPS/LTA extract from BB12. The inhibitory concentrations in both cases likely reflect the physico-chemical properties of LTAs with the highest efficacy below the critical micelle concentration, and therefore we ascribe the main inhibitory effect to LTAs for the BB12 isolated EPS/LTA extract as well. In conclusion we present increased biosynthesis of lipoteichoic acids of BB12 co-incubated with human Caco-2 cells and evidence that LTA serve as important cell wall factors involved in adhesion to these human enterocyte-like cells.
Project description:Comparison of the growth of Bifidobacterium animalis subsp. lactis BB12 in MRS (without carbon source) with either 2% XOS (xylo-oligosaccharides) or 2% glucose using whole-genome transcriptome analysis.
Project description:The global transcriptome of the Bifidobacterium animalis subsp. lactis Bl-04 was analyzed during exponential growth on 11 prebiotic carbohydrates and glucose to identify the specific gene cluster differentially upregulated in response to each carbohydrate.
Project description:The global transcriptome of the Bifidobacterium animalis subsp. lactis Bl-04 was analyzed during exponential growth on 11 prebiotic carbohydrates and glucose to identify the specific gene cluster differentially upregulated in response to each carbohydrate. Affymetrix hybridization experiments were performed to compare the differential transcriptional profiles of the B. lactis Bl-04 at the early-log (OD600nm 0.3-0.5) phase. 12 carbohydrates were tested with two technical replicates to each condition for a total of 24 hybridizations.
Project description:Modulation of gut microbiota through probiotic supplementation is an interesting strategy to prevent obesity We use microarrays to study the global genome expression of C. elegans fed with the probiotic strain Bifidobacterium animalis sbsp. lactis CECT 8145 Wild type strain N2 of C. elegans was cutured in Nematode Growth medium (NGM, control fed) or NGM with a bacterial lawn fed of the strain B. animalis subsp. lactis CECT 8145, until reach young adult stage. Worm population were age-synchronized. RNA was isolated from each populations (control and treated) using RNAasy Kit (Qiagen) and hybridizated on Affymetrix microarrays.
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).