Project description:This study aimed to investigate the effects of oral administration of lactic acid bacteria (LAB) on gene expression in murine ileum. Two LAB strains, Lactococcus lactis subsp. lactis C59 and Lactobacillus rhamnosus GG, were administered to mice for 2 weeks. Microarray analysis was performed using total RNA from upper and lower ileum to detail the gene expression of 3 groups; control, C59-administered and GG-administered. Gene expression of upper ileum was less affected by administered strains than that of lower ileum and the latter was strain-specifically affected.
Project description:This study aimed to investigate the effects of oral administration of lactic acid bacteria (LAB) on gene expression in murine ileum. To evaluate the strain specific and dose effects of LAB on the gene expression of distal ileum, Lactococcus lactis C59 and Lactobacillus rhamnosus GG were administered at a dose of 1 x 107 cells (10^7), 1 x 108 (10^8) cells or 1 x 109 (10^9) cells Microarray analysis was performed using total RNA from distal ileum to detail the gene expression of 7 groups; control, C59- and GG-administered at a dose of 1 x 107 cells (10^7), 1 x 108 (10^8) cells or 1 x 109 (10^9) cells. Gene expression patterns were clustered by administered strains. Several genes involved in immune system are up-regulated in the lower intestine in the presence of GG and down-regulated in the presence of C59.
Project description:The presence of tagatose in Lactobacillus rhamnosus strain GG caused induction of a large number of genes associated with carbohydrate metabolism including the phosphotransferase system. In addition, these results indicate the tagatose enhanced the growth of Lactobacillus casei 01 and Lactobacillus rhamnosus strain GG and their probiotic activities by activating tagatose-associated PTS networks. Two-condition experiment, Lactobacillus rhamnosus GG with glucose vs. Lactobacillus rhamnosus GG with tagatose. For preparing the total RNA, Lactobacillus rhamnosus GG cells were grown at 37M-BM-0C in prebiotic minimum medium supplemented with 2% glucose or tagatose for 24 h.
Project description:Background: milk is considered an important source of bioactive peptides, which can be produced by endogenous or starter bacteria, such as lactic acid bacteria, that are considered effective and safe producers of food-grade bioactive peptides. Among the various types of milk, donkey milk has been gaining more and more attention for its nutraceutical properties. Methods: Lactobacillus rhamnosus 17D10 and Lactococcus lactis subsp. cremoris 40FEL3 were selected for their ability to produce peptides from donkey milk. The endogenous peptides and those obtained after bacterial fermentation were assayed for their antioxidant, antibacterial and antiviral activities. The peptide mixtures were characterized by means of LC-MS/MS, and then analyzed in silico using the Milk Bioactive Peptide DataBase. Results: the peptides produced by the two selected bacteria enhanced the antioxidant activity and reduced E. coli growth. Only the peptides produced by L. rhamnosus 17D10 were able to reduce S. aureus growth. All the peptide mixtures were able to inhibit the replication of HSV-1 by more than 50%. Seventeen peptides were found to have 60% sequence similarity with already known bioactive peptides. Conclusion: a lactic acid bacterium fermentation process is able to enhance the value of donkey milk through bioactivities that are important for human health.
Project description:The presence of tagatose in Lactobacillus rhamnosus strain GG caused induction of a large number of genes associated with carbohydrate metabolism including the phosphotransferase system. In addition, these results indicate the tagatose enhanced the growth of Lactobacillus casei 01 and Lactobacillus rhamnosus strain GG and their probiotic activities by activating tagatose-associated PTS networks.
Project description:We have developed a microfluidics-based in vitro model of the human gut allowing co-culture of human and microbial cells and subsequent multi-omic assessment of the effect of the co-culture on the host transcriptome. We compare the transcriptional changes induced in the human epithelial cell line, Caco-2 after co-culture with Lactobacillus rhamnosus GG or a consortium of Lactobacillus rhamnosus GG and Bacteroides caccae.
Project description:Transcriptional profiling of probiotic Lactobacillus rhamnosus strain GG mid-exponential pH-controlled bioreactor cultures before and after exposure to bovine bile (0.2% ox gall). Keywords: bile, stress response Cell samples from four biological replicates were harvested right before (time point 0 min) and 10, 30 and 120 min after bile treatment. Each sample was compared to a common reference sample (time point 0 min, mid-exponential growth phase Lactobacillus rhamnosus GG cultures). A total of 12 hybridizations were performed using balanced dye-swap design. Dyes were balanced between compared sample pairs and between biological replicates.
Project description:Transcriptional profiling of probiotic Lactobacillus rhamnosus strain GG mid-exponential pH-controlled bioreactor cultures before and after exposure to bovine bile (0.2% ox gall). Keywords: bile, stress response
Project description:Numerous studies have shown that resistance to oxidative stress is crucial to stay healthy and to reduce the adverse effects of aging. Accordingly, nutritional interventions using antioxidant food-grade compounds or food products are currently an interesting option to help improve health and quality of life in the elderly. Live lactic acid bacteria (LAB) administered in food, such as probiotics, may be good antioxidant candidates. Nevertheless, information about LAB-induced oxidative stress protection is scarce. To identify and characterize new potential antioxidant probiotic strains, we have developed a new functional screening method using the nematode Caenorhabditis elegans as host. C. elegans were fed on different LAB strains (78 in total) and nematode viability was assessed after oxidative stress (3mM and 5mM H2O2). One strain, identified as Lactobacillus rhamnosus CNCM I-3690, protected worms by increasing their viability by 30% and, also, increased average worm lifespan by 20%. We performed a transcriptomic analysis of C. elegans fed with this strain and showed that increased lifespan is correlated with differential expression of the DAF-16/insulin-like pathway, which is highly conserved in humans. Gene expression in C. elegans wild-type strain (N2) was analyzed in worm populations fed with E. coli OP50 (control condition) or the corresponding LAB (Lactobacillus rhamnosus CNCM I-3690 or Lactobacillus rhamnosus CNCM I-4317) . Three days and ten days feeding period was analyzed.
Project description:Transcriptional profiling of probiotic Lactobacillus rhamnosus GG during growth in industrial-type whey medium in pH-controlled bioreactor cultures at two different growth pH: 4.8 and 5.8. Keywords: growth phase, growth pH