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:Bifidobacterium animalis subsp. lactis BL-99 with fructo-oligosaccharide alleviates constipation in mice by modulating gut microbiota
Project description:A huge number of microorganisms are colonized in human gut and the balance of their composition is closely related to human health. Recently, many probiotics such as bifidobacteria or lactobacilli have been introduced in our life as effective agents. However, we have not well understood their beneficial mechanisms including host-bacterial crosstalk To analyze the differences of gene expression between BA- or BL-associated murine colonic epithelium, we performed comparative transcriptomic analysis. Bifidobacterium adolescentis (BA)-associated mice and Bifidobacterium longum (BL)-associated mice were used. Colonic epithelium was isolated and gene expression profile was analyzed. Each 3 samples were analyzed.
Project description:Analysis of differentiated Caco-2 intestinal epithelial cell line cocultured with probiotics L. acidophilus NCFM™, B. lactis 420, L. salivarius Ls-33 bacterial cells or treated with cell-free supernatant, and with E. coli O157:H7 cell-free supernatant. Lactobacillus and Bifidobacterium are important genera suggested to be beneficial for human health and E. coli O157:H7 is a pathogen causing hemorrhagic colitis and hemolytic uremic syndrome. Results provide insight into the mechanisms underlying the beneficial effects of probiotics on intestinal epithelial cells and a comparison to pathogenic E. coli.
Project description:Commercial probiotic bacteria must be tested for acquired antibiotic resistance elements to avoid potential transfer to pathogens. The European Food Safety Authority recommends testing resistance using microdilution culture techniques previously used to establish inhibitory thresholds for the Bifidobacterium genus. Many Bifidobacterium animalis subsp. lactis strains exhibit increased resistance to tetracycline, historically attributed to the ribosomal protection gene tet(W). However, some strains that harbor genetically identical tet(W) genes show various inhibition levels suggesting that other genetic elements also contribute to observed differences. Here, we adapted several molecular assays to confirm the inhibition of B. animalis subsp. lactis strains Bl-04 and HN019, and employed RNA-seq to assess the transcriptional differences related to genomic polymorphisms. We detected specific stress responses to the antibiotic by correlating ATP concentration to viable genome copies from droplet digital PCR, and found that the bacteria were still metabolically active in high drug concentrations. Transcriptional analyses revealed that several polymorphic regions, particularly a novel multi-drug efflux transporter, were differentially expressed between the strains in each experimental condition, likely having phenotypic effects. We also found that the tet(W) gene was up-regulated only during sub-inhibitory tetracycline concentrations, while two novel tetracycline resistance genes were up-regulated at high concentrations. Furthermore, many genes involved in amino acid metabolism and transporter function were up-regulated while genes for complex carbohydrate utilization, protein metabolism, and CRISPR-Cas systems were down-regulated. These results provide high-throughput means for assessing antibiotic resistance and determine the genetic network that contributes to the global tetracycline response between two highly related probiotic strains.
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: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 activation of pulmonary endothelial cells (ECs) triggers the occurrence of lung injury and is a hallmark of sepsis-associated acute respiratory distress syndrome(ARDS). Aberrant metabolism favoring glycolysis plays a pivotal role in the pathogenesis of sepsis-induced EC activation. Herein we demonstrate that glycolysis-related histone lactylation, represented by H3K14 lactylation (H3K14la), drives sepsis-associated EC activation and lung injury. Accordingly, H3K14la level is elevated in injured lung tissue and activated ECs. Inhibition of lactate production suppresses both H3K14la levels and EC activation in response to lipopolysaccharide (LPS). We also show that lactate-dependent H3K14la is enriched at the promoters of ferroptosis-related genes, thereby inducing ferroptosis in ECs, and inhibiting ferroptosis effectively ameliorates EC activation. Taken together, elevated lactate in sepsis modulates EC activation and lung injury via histone lactylation and manipulation of glycolysis/H3K14la/ferroptosis axis may provide novel therapeutic approaches for the treatment of sepsis-associated ARDS.