Project description:Some commensal bacteria stimulate the immune system but do not present specific antigenicity. Such adjuvant effects have been reported for the bacterial species Lactobacillus plantarum. To study in vivo human responses to L. plantarum, a randomised double-blind placebo-controlled cross-over study was performed. Healthy adults were provided preparations of living and heat-killed L. plantarum bacteria, biopsies were taken from the intestinal mucosa and altered transcriptional profiles were analysed. Transcriptional profiles of human epithelia displayed striking differences upon exposure to living L. plantarum bacteria harvested at different growth phases. Modulation of NF-κB-dependent pathways was central among the major altered cellular responses. This unique in vivo study shows which cellular pathways are associated with the induction of immune tolerance in mucosal tissues towards common adjuvanticity possessing lactobacilli. Keywords: mucosal response of healthy adult humans to lactic acid bacteria This study was set up according to a randomised double-blind cross-over placebo-controlled design. It contains transcriptional profiles from biopsies from 8 healthy individuals after oral intake of three different growth stages of Lactobacillus plantarum or placebo control. In total, this study includes data from 8 individuals x 4 treatments=32 arrays.
Project description:In this study, we examined Caco-2 cell gene expression after infection with E. coli (Ec), Lactobacillus plantarum (Lp) and the combination of the two (mix) Keywords: Lactobacillus plantarum and E. coli influences on Caco2 cells gene expression
Project description:Mannose-specific interactions of Lactobacillus plantarum 299v with jejunal epithelium were investigated using an in situ pig small intestinal segment perfusion (SISP) model. L. plantarum 299v wildtype strain was compared to two isogenic mutant strains either lacking the gene encoding for the mannose-specific adhesin (msa) or sortase (srtA; responsible for anchoring of cell surface proteins like Msa to the cell wall). Salmonella typhimurium served as a positive control for gene expression analysis. Scrapings from jejunal segments were collected after perfusion with bacterial suspensions or PBS (control) for 4 or 8 hours, and host gene expression was assessed using a home-made cDNA porcine microarray. Keywords: host-microbe interaction, Lactobacillus plantarum, mannose-specific adhesion A Small Intestinal Segment Perfusion (SISP) test was performed using 4 pigs. 10 segments were prepared in the jejunum of each pig and perfused with Lactobacillus plantarum 299v wildtype, Lactobacillus plantarum 299v msa mutant strain, Lactobacillus plantarum 299v srtA mutant strain, Salmonella typhimurium or PBS (control) for 4 or 8 hours. Pooled samples from each treatment at each timepoint were used for microarray analysis. 8 comparisons were done: L. plantarum wildtype vs control (4 hours), L. plantarum wildtype vs control (8 hours), L. plantarum msa mutant vs control (4 hours), L. plantarum msa mutant vs control (8 hours), L. plantarum srt mutant vs control (4 hours), L. plantarum srt mutant vs control (8 hours), S. typhimurium vs control (8 hours), samples taken at the beginning of the experiment vs control (8 hours). Dye-swaps were performed for each comparison.
Project description:In this experiment we analyzed the impact of the disruption of trxB1in Lactobacillus plantarum at the transcriptome level. Furthermore we studied the effect of 3.5 mM peroxide effect on both Lactobacillus plantarum wild type (strain WCFS1) and a trxB1 mutant (strain NZ7608). Keywords: mutant analysis of trxB1, hydrogen peroxide stress
Project description:Background: Lactobacillus plantarum is found in a variety of fermented foods and as such, consumed for centuries. Some strains are natural inhabitants of the human gastro-intestinal tract and like other Lactobacillus species, L. plantarum has been extensively studied for its immunomodulatory properties and its putative health-promoting effects (probiotic). Being the first line of host defense intestinal epithelial cells (IEC) are key players in the recognition and initiation of responses to gut microorganisms. Results: Using high-density oligonucleotide microarrays we examined the gene expression profiles of differentiated Caco-2 cells exposed to various doses of L. plantarum. In addition, the effects were correlated to monolayer permeability studies and measurement of lactic acid production. A transcriptional dose-dependent IEC response to L. plantarum was found. Incubation of Caco-2 with a low bacterial dose induced a specific response, not due to cytotoxicity or production of lactic acid, including modulation of cell cycle and cell signaling functions. Exposure of Caco-2 cells to larger amounts of bacteria, accompanied by the production of lactic acid and glucose depletion, provoked increased permeability and supposed non-specific defense responses. Conclusions: These results suggest that IEC are able to sense and react to the presence of gut bacteria. This study provides the first description of global transcriptional response of human IEC to a commensal lactic acid bacterium, and it shows the importance of choosing physiological bacterial doses to prevent the observation of non-specific host reactions. Caco-2 cells were exposed for 10h to Lactobacillus. Fourteen samples are analyzed: 4 control Caco-2, 4 Caco-2 exposed to a low dose (10) of Lactobacillus, 4 Caco-2 exposed to a medium dose (100) of Lactobacillus, 2 Caco-2 exposed to a high dose (1000) of Lactobacillus. All 14 RNA samples are labeled with Cy5 and hybridized to a common reference (undifferentiated Caco-2, untreated) RNA labeled with Cy3
Project description:In order to understand LBG derived galacto-manno-oligosaccharides utilization by a probiotic bacterium, Lactobacillus plantarum WCFS1, we have grown Lactobacillus plantarum WCFS1 (in duplicates) till mid log phase (OD600nm ~0.5, 10 h) in carbon free MRS (de Man, Rogosa Sharpe ) media containing either galacto-manno-oligosaccharides, mannose, glucose or galactose (1% w/v) as the sole carbon source.
Project description:Effect of Lactobacillus plantarum MB452 on the gene expression of the intestinal epithelial cell line Caco-2 using a reference design Experiment Overall Design: Effect of Lactobacillus plantarum MB452 on the gene expression of the intestinal epithelial cell line Caco-2 using a reference design
Project description:Gut microbiota is an unignored target in maintaining intestinal homeostasis due to its regulatory effects on intestinal health through multiple mechanisms, including enhancing intestinal barriers, modulating microbial diversity, secreting various metabolites, etc. Bacteriocins produced by probiotics have been gradually proved vital for intestinal diseases intervention, however, the corresponding mechanisms have received less attention and the whole story of their regulative activities are hard to be fully uncovered. The two-peptide Plantaricin NC8 (PLNC8), coded by gene plnc8, is a bacteriocin ubiquitously produced by Lactobacillus plantarum, has been regarded as the potential vital bacteriocin for the anti-inflammatory effects of Lactobacillus plantarum. This study exploited CRISPR-cas9 and prokaryotic gene overexpression techniques to construct the plnc8 strains for the anti-inflammatory mechanism investigation. Based on the metagenomics, transcriptomics and metabolomics analysis, the anti-enteritis mechanism of PLNC8 systematically in DSS-induced enteritis models were comprehensively revealed. PLNC8 induced alterations in the composition of gut microbiota composition, promoting the alterations of multiple probiotics such as Eubacterium plexicaudatum, Doreasp.5-2, Enterococcus cecorum and Prevotella oulorum. Besides, various metabolites produced by the gut microbiota were influenced, and the key metabolites of xanthine, hypoxanthine, and L-histidine were regulated via purine and histidine metabolic pathways. These metabolites further inhibited p38 MAPK phosphorylation of enterocytes induced by DSS. Ultimately, the intestinal barrier repairment and anti- enteritis were achieved, proving the anti-enteritis effects of PLNC8 via microbe-metabolites-enterocyte axis.
Project description:Whole genome transcriptional profiling was used to characterize the response of Lactobacillus plantarum WCFS1 human isolate during challenge with oleuropein. Twelve independent experiments were performed and mixed at random in groups of four for total of three RNA samples. The transcriptional profile shows that Lactobacillus plantarum WCFS1 adapts its metabolic capacity to acquire certain carbohydrates and repress the expression of genes involved in fatty acid biosyntheis. The transcriptomic datasets also revealed the downregulation of genes related to the biosynthesis of capsular polysaccharides and genes coding for ABC-type transporters. In addition, induction of oligopeptide permeases is also part of the response of Lactobacillus plantarum WCFS1 to oleuropein.