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Faecalibacterium prausnitzii is an anti-inflammatory commensal bacterium identified on the basis of human clinical data. The mechanisms underlying its beneficial effects are still unknown. Gnotobiotic mice harboring F. prausnitzii (A2-165) and Escherichia coli (K-12 JM105) were subjected to 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced acute colitis. The inflammatory colitis scores and a gas chromatography-time of flight (GC/TOF) mass spectrometry-based metabolomic profile were monitored indoi:10.1128/mbio.00300-15 pmid:25900655 pmcid:PMC4453580 fatcat:usi5bwvobbd6fd4xahzmec3xty
more »... blood, ileum, cecum, colon, and feces in gnotobiotic mice. The potential anti-inflammatory metabolites were tested in vitro. We obtained stable E. coli and F. prausnitzii-diassociated mice in which E. coli primed the gastrointestinal tract (GIT), allowing a durable and stable establishment of F. prausnitzii. The disease activity index, histological scores, myeloperoxidase (MPO) activity, and serum cytokine levels were significantly lower in the presence of F. prausnitzii after TNBS challenge. The protective effect of F. prausnitzii against colitis was correlated to its implantation level and was linked to overrepresented metabolites along the GIT and in serum. Among 983 metabolites in GIT samples and serum, 279 were assigned to known chemical reactions. Some of them, belonging to the ammonia (α-ketoglutarate), osmoprotective (raffinose), and phenolic (including anti-inflammatory shikimic and salicylic acids) pathways, were associated with a protective effect of F. prausnitzii, and the functional link was established in vitro for salicylic acid. We show for the first time that F. prausnitzii is a highly active commensal bacterium involved in reduction of colitis through in vivo modulation of metabolites along the GIT and in the peripheral blood.
doi:10.3389/fcimb.2014.00039 pmid:24734220 pmcid:PMC3975094 fatcat:du5s4uhnmrcrrmus3sjhbkos4a
Copyright © 2016 Mosca, Leclerc and Hugot. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). ...doi:10.3389/fmicb.2016.00455 pmid:27065999 pmcid:PMC4815357 fatcat:457cmn4rffaadhxts6mxc2pt4y
Copyright © 2021 Clauss, Gérard, Mosca and Leclerc. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). ...doi:10.3389/fnut.2021.637010 pmid:34179053 pmcid:PMC8222532 fatcat:dojl4ylenbf6hpv3fnk7gwsxam
Marion are former employees of Rx&D. Dr. Marion received an honorarium from Integrated Research for analysis of the data and drafting the manuscript. Dr. ... Leclerc is past co-chair of the Rx&D Medical/ Clinical Committee. Correspondence may be directed to: Mr. Normand Laberge, Montréal, QC H2R 2V7; Table S1 . ...pmid:23968618 pmcid:PMC3517875 fatcat:jlqnlbaf6ffsdjgm2zp3spqpra
Dietary fibers impact gut colonic health, through the production of short-chain fatty acids. A low-fiber diet has been linked to lower bacterial diversity, obesity, type 2 diabetes, and promotion of mucosal pathogens. Glycoside hydrolases (GHs) are important enzymes involved in the bacterial catabolism of fiber into short-chain fatty acids. However, the GH involved in glycan breakdown (adhesion, hydrolysis, and fermentation) are organized in polysaccharide utilization loci (PUL) with complexdoi:10.3389/fmicb.2021.632567 pmid:34690938 pmcid:PMC8527192 fatcat:wvl6luviozb6dh4tif2byq3imu
more »... ularity. Our goal was to explore how the capacity of strains, from the Bacteroidetes phylum, to grow on fiber could be predicted from their genome sequences. We designed an in silico pipeline called FiberGrowth and independently validated it for seven different fibers, on 28 genomes from Bacteroidetes-type strains. To do so, we compared the existing GH annotation tools and built PUL models by using published growth and gene expression data. FiberGrowth's prediction performance in terms of true positive rate (TPR) and false positive rate (FPR) strongly depended on available data and fiber: arabinoxylan (TPR: 0.89 and FPR: 0), inulin (0.95 and 0.33), heparin (0.8 and 0.22) laminarin (0.38 and 0.17), levan (0.3 and 0.06), mucus (0.13 and 0.38), and starch (0.73 and 0.41). Being able to better predict fiber breakdown by bacterial strains would help to understand their impact on human nutrition and health. Assuming further gene expression experiment along with discoveries on structural analysis, we hope computational tools like FiberGrowth will help researchers prioritize and design in vitro experiments.
Healthcare Policy | Politiques de Santé
Marion are former employees of Rx&D. Dr. Marion received an honorarium from Integrated Research for analysis of the data and drafting the manuscript. Dr. ... Leclerc is past co-chair of the Rx&D Medical/ Clinical Committee. Correspondence may be directed to: Mr. Normand Laberge, Montréal, QC H2R 2V7; Table S1 . ...doi:10.12927/hcpol.2012.23130 fatcat:hoj5v2ac5fg77e3uknew6wvbey
A laboratory-scale continuously mixed anaerobic digester was inoculated with a mix of anaerobic sludge and fed with glucose. The startup strategy was progressive and chemical analyses were done to evaluate digester performance from day 1 to day 107. In parallel, Archaeal community dynamics were monitored by SSCP analysis of the V3 region of 16S rDNA genes and further characterized by partial sequencing of 16S rDNA genes. At day 1 the inoculum contained at least five distinct Archaeal peaksdoi:10.1111/j.1574-6941.2001.tb00772.x pmid:11137601 fatcat:enks4npbbzfbbnkbwqon54f7sq
more »... to known methanogenic species. The dominant peak was very close to Methanosaeta concilli, the remaining species being members of the Methanobacteriales and Methanomicrobiales. A rapid shift of the Archaeal population was observed during the experiment. At day 21 Methanobacterium formicicum, which was not detected at day 1, became the dominant methanogenic species in the bioreactor and remained so until the end of the experiment. ß
Mucosal healing has become a therapeutic goal to achieve stable remission in patients with inflammatory bowel diseases. To achieve this objective, overlapping actions of complex cellular processes, such as migration, proliferation, and differentiation, are required. These events are longitudinally and tightly controlled by numerous factors including a wide range of distinct regulatory proteins. However, the sequence of events associated with colon mucosal repair after colitis and the evolutiondoi:10.3748/wjg.v25.i27.3572 pmid:31367158 pmcid:PMC6658396 fatcat:3vxu5e2iofemffqplowp6csjwy
more »... f the luminal content characteristics during this process have been little studied. To document the evolution of colon mucosal characteristics during mucosal healing using a mouse model with chemically-induced colitis. C57BL/6 male mice were given 3.5% dextran sodium sulfate (DSS) in drinking water for 5 d. They were euthanized 2 (day 7), 5 (day 10), 8 (day 13), and 23 (day 28) d after DSS removal. The colonic luminal environment and epithelial repair processes during the inflammatory flare and colitis resolution were analyzed with reference to a non-DSS treated control group, euthanized at day 0. Epithelial repair events were assessed histo-morphologically in combination with functional permeability tests, expression of key inflammatory and repairing factors, and evaluation of colon mucosa-adherent microbiota composition by 16S rRNA sequencing. The maximal intensity of colitis was concomitant with maximal alterations of intestinal barrier function and histological damage associated with goblet cell depletion in colon mucosa. It was recorded 2 d after termination of the DSS-treatment, followed by a progressive return to values similar to those of control mice. Although signs of colitis were severe (inflammatory cell infiltrate, crypt disarray, increased permeability) and associated with colonic luminal alterations (hyperosmolarity, dysbiosis, decrease in short-chain fatty acid content), epithelial healing processes were launched early during the inflammatory flare with increased gene expression of certain key epithelial repair modulators, including transforming growth factor-β, interleukin (Il)-15, Il-22, Il-33, and serum amyloid A. Whereas signs of inflammation progressively diminished, luminal colonic environment alterations and microscopic abnormalities of colon mucosa persisted long after colitis induction. This study shows that colon repair can be initiated in the context of inflamed mucosa associated with alterations of the luminal environment and highlights the longitudinal involvement of key modulators.
Copyright © 2019 Laville, Perrier, Bejar, Maresca, Esque, Tauzin, Bouhajja, Leclerc, Drula, Henrissat, Berdah, Di Pasquale, Robe and Potocki-Veronese. ...doi:10.3389/fmicb.2019.01286 pmid:31275257 pmcid:PMC6593285 fatcat:sypqh7bbf5an7o3wrvdf632dcu
., Leclerc, M., Gaudichon, C., Blachier, F. (2018). ... -M., Fromentin, G., Tomé, D., Souchon, I., Leclerc, M., Gaudichon, C., Blachier, F. (2018). ...doi:10.1002/mnfr.201700570 pmid:28994235 fatcat:tnwemkm4mbcjhds3jjztvvn77a
Background Despite the importance of the mucosal interface between microbiota and the host in gut homeostasis, little is known about the mechanisms of bacterial gut colonization, involving foraging for glycans produced by epithelial cells. The slow pace of progress toward understanding the underlying molecular mechanisms is largely due to the lack of efficient discovery tools, especially those targeting the uncultured fraction of the microbiota. Results Here, we introduce andoi:10.1186/s40168-020-00911-z pmid:33004077 fatcat:tvuqj54m7rfl5jousufjp4avz4
more »... t metagenomic approach based on droplet microfluidics, to screen fosmid libraries. Thousands of bacterial genomes can be covered in 1 h of work, with less than ten micrograms of substrate. Applied to the screening of the mucosal microbiota for β-N-acetylgalactosaminidase activity, this approach allowed the identification of pathways involved in the degradation of human gangliosides and milk oligosaccharides, the structural homologs of intestinal mucin glycans. These pathways, whose prevalence is associated with inflammatory bowel diseases, could be the result of horizontal gene transfers with Bacteroides species. Such pathways represent novel targets to study the microbiota-host interactions in the context of inflammatory bowel diseases, in which the integrity of the mucosal barrier is impaired. Conclusion By compartmentalizing experiments inside microfluidic droplets, this method speeds up and miniaturizes by several orders of magnitude the screening process compared to conventional approaches, to capture entire metabolic pathways from metagenomic libraries. The method is compatible with all types of (meta)genomic libraries, and employs a commercially available flow cytometer instead of a custom-made sorting system to detect intracellular or extracellular enzyme activities. This versatile and generic workflow will accelerate experimental exploration campaigns in functional metagenomics and holobiomics studies, to further decipher host-microbiota relationships.
The human intestine hosts a complex bacterial community that plays a major role in nutrition and in maintaining human health. A functional metagenomic approach was used to explore the prebiotic breakdown potential of human gut bacteria, including non-cultivated ones. Two metagenomic libraries, constructed from ileum mucosa and fecal microbiota, were screened for hydrolytic activities on the prebiotic carbohydrates inulin, fructo-oligosaccharides, xylo-oligosaccharides, galacto-oligosaccharidesdoi:10.1371/journal.pone.0072766 pmid:24066026 pmcid:PMC3774763 fatcat:zexvdfxmwng5zdhvihnzav5e5a
more »... nd lactulose. The DNA inserts of 17 clones, selected from the 167 hits that were identified, were pyrosequenced in-depth, yielding in total 407, 420 bp of metagenomic DNA. From these sequences, we discovered novel prebiotic degradation pathways containing carbohydrate transporters and hydrolysing enzymes, for which we provided the first experimental proof of function. Twenty of these proteins are encoded by genes that are also present in the gut metagenome of at least 100 subjects, whatever are their ages or their geographical origin. The sequence taxonomic assignment indicated that still unknown bacteria, for which neither culture conditions nor genome sequence are available, possess the enzymatic machinery to hydrolyse the prebiotic carbohydrates tested. The results expand the vision on how prebiotics are metabolized along the intestine, and open new perspectives for the design of functional foods.
Characterization of the formation of the protein corona of TiO2 nanoparticles as a function of the main nanoparticle properties and investigation of potential relationship with the cytotoxicity nanoparticles induce in vitro in human lung cells.doi:10.1039/d0ra08429h pmid:35517183 pmcid:PMC9058407 fatcat:u5x57jp2fffijjkhhx5ps6neqm
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