801
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McCaughey LC, Grinter R, Josts I, Roszak AW, Waløen KI, Cogdell RJ, Milner J, Evans T, Kelly S, Tucker NP, Byron O, Smith B, Walker D. Lectin-like bacteriocins from Pseudomonas spp. utilise D-rhamnose containing lipopolysaccharide as a cellular receptor. PLoS Pathog 2014; 10:e1003898. [PMID: 24516380 PMCID: PMC3916391 DOI: 10.1371/journal.ppat.1003898] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 12/10/2013] [Indexed: 11/24/2022] Open
Abstract
Lectin-like bacteriocins consist of tandem monocot mannose-binding domains and display a genus-specific killing activity. Here we show that pyocin L1, a novel member of this family from Pseudomonas aeruginosa, targets susceptible strains of this species through recognition of the common polysaccharide antigen (CPA) of P. aeruginosa lipopolysaccharide that is predominantly a homopolymer of d-rhamnose. Structural and biophysical analyses show that recognition of CPA occurs through the C-terminal carbohydrate-binding domain of pyocin L1 and that this interaction is a prerequisite for bactericidal activity. Further to this, we show that the previously described lectin-like bacteriocin putidacin L1 shows a similar carbohydrate-binding specificity, indicating that oligosaccharides containing d-rhamnose and not d-mannose, as was previously thought, are the physiologically relevant ligands for this group of bacteriocins. The widespread inclusion of d-rhamnose in the lipopolysaccharide of members of the genus Pseudomonas explains the unusual genus-specific activity of the lectin-like bacteriocins. Due to rapidly increasing rates of antibiotic resistance observed among Gram-negative pathogens, such as Pseudomonas aeruginosa, there is an urgent requirement for novel approaches to the treatment of bacterial infections. Lectin-like bacteriocins are highly potent protein antibiotics that display an unusual ability to kill a select group of bacteria within a specific genus. In this work, we show how the lectin-like protein antibiotic, pyocin L1, can kill Pseudomonas aeruginosa with extraordinary potency through specific binding to the common polysaccharide antigen (CPA) of P. aeruginosa lipopolysaccharide. The CPA is predominantly a homopolymer of the sugar d-rhamnose that although generally rare in nature is found frequently as a component of the lipopolysaccharide of members of the genus Pseudomonas. The targeting of d-rhamnose containing polysaccharides by pyocin L1 and a related lectin-like protein antibiotic, putidacin L1, explains the unusual genus- specific killing activity of the lectin-like bacteriocins. As we learn more about the link between changes to the microbiome and a range of chronic diseases there is a growing realisation that the ability to target specific bacterial pathogens while maintaining the normal gut flora is a desirable property for next generation antibiotics.
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Affiliation(s)
- Laura C. McCaughey
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Rhys Grinter
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Inokentijs Josts
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Aleksander W. Roszak
- WestCHEM, School of Chemistry, College of Science and Engineering, University of Glasgow, Glasgow, United Kingdom
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Kai I. Waløen
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- School of Life Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Richard J. Cogdell
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Joel Milner
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Tom Evans
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Sharon Kelly
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Nicholas P. Tucker
- Strathclyde Institute for Pharmaceutical and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Olwyn Byron
- School of Life Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Brian Smith
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Daniel Walker
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- * E-mail:
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802
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Blais Lecours P, Marsolais D, Cormier Y, Berberi M, Haché C, Bourdages R, Duchaine C. Increased prevalence of Methanosphaera stadtmanae in inflammatory bowel diseases. PLoS One 2014; 9:e87734. [PMID: 24498365 PMCID: PMC3912014 DOI: 10.1371/journal.pone.0087734] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 12/28/2013] [Indexed: 12/12/2022] Open
Abstract
Background The gut microbiota is associated with the modulation of mucosal immunity and the etiology of inflammatory bowel diseases (IBD). Previous studies focused on the impact of bacterial species on IBD but seldom suspected archaea, which can be a major constituent of intestinal microbiota, to be implicated in the diseases. Recent evidence supports that two main archaeal species found in the digestive system of humans, Methanobrevibacter smithii (MBS) and Methanosphaera stadtmanae (MSS) can have differential immunogenic properties in lungs of mice; with MSS but not MBS being a strong inducer of the inflammatory response. We thus aimed at documenting the immunogenic potential of MBS and MSS in humans and to explore their association with IBD. Methods To validate the immunogenicity of MBS and MSS in humans, peripheral blood mononuclear cells from healthy subjects were stimulated with these two microorganisms and the production of inflammatory cytokine TNF was measured by ELISA. To verify MBS and MSS prevalence in IBD, stool samples from 29 healthy control subjects and 29 patients suffering from IBD were collected for DNA extraction. Plasma was also collected from these subjects to measure antigen-specific IgGs by ELISA. Quantitative PCR was used for bacteria, methanogens, MBS and MSS quantification. Results Mononuclear cells stimulated with MSS produced higher concentrations of TNF (39.5 ng/ml) compared to MBS stimulation (9.1 ng/ml). Bacterial concentrations and frequency of MBS-containing stools were similar in both groups. However, the number of stool samples positive for the inflammatory archaea MSS was higher in patients than in controls (47% vs 20%). Importantly, only IBD patients developed a significant anti-MSS IgG response. Conclusion The prevalence of MSS is increased in IBD patients and is associated with an antigen-specific IgG response.
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Affiliation(s)
- Pascale Blais Lecours
- Centre de recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec, Québec, Canada
| | - David Marsolais
- Centre de recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec, Québec, Canada
- Département de médecine, Faculté de médecine, Université Laval, Québec, QC, Canada
| | - Yvon Cormier
- Centre de recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec, Québec, Canada
- Département de médecine, Faculté de médecine, Université Laval, Québec, QC, Canada
| | | | | | | | - Caroline Duchaine
- Centre de recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec, Québec, Canada
- Département de biochimie, de microbiologie et de bioinformatique, Faculté des sciences et de génie, Université Laval, Québec, Québec, Canada
- * E-mail:
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803
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Ooi JH, Waddell A, Lin YD, Albert I, Rust LT, Holden V, Cantorna MT. Dominant effects of the diet on the microbiome and the local and systemic immune response in mice. PLoS One 2014; 9:e86366. [PMID: 24489720 PMCID: PMC3906035 DOI: 10.1371/journal.pone.0086366] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 12/06/2013] [Indexed: 12/22/2022] Open
Abstract
Outside the nutrition community the effects of diet on immune-mediated diseases and experimental outcomes have not been appreciated. Investigators that study immune-mediated diseases and/or the microbiome have overlooked the potential of diet to impact disease phenotype. We aimed to determine the effects of diet on the bacterial microbiota and immune-mediated diseases. Three different laboratory diets were fed to wild-type mice for 2 weeks and resulted in three distinct susceptibilities to dextran sodium sulfate (DSS)-induced colitis. Examination of the fecal microbiota demonstrated a diet-mediated effect on the bacteria found there. Broad-spectrum antibiotics disturbed the gut microbiome and partially eliminated the diet-mediated changes in DSS susceptibility. Dietary changes 2 days after DSS treatment were protective and suggested that the diet-mediated effect occurred quickly. There were no diet-mediated effects on DSS susceptibility in germ-free mice. In addition, the diet-mediated effects were evident in a gastrointestinal infection model (Citrobacter rodentium) and in experimental autoimmune encephalomyelitis. Taken together, our study demonstrates a dominant effect of diet on immune-mediated diseases that act rapidly by changing the microbiota. These findings highlight the potential of using dietary manipulation to control the microbiome and prevent/treat immune-mediated disease.
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Affiliation(s)
- Jot Hui Ooi
- Center for Molecular Immunology and Infectious Disease, Department of Biochemistry and Molecular Biology, Department of Veterinary and Biomedical Science, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Amanda Waddell
- Center for Molecular Immunology and Infectious Disease, Department of Biochemistry and Molecular Biology, Department of Veterinary and Biomedical Science, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Yang-Ding Lin
- Center for Molecular Immunology and Infectious Disease, Department of Biochemistry and Molecular Biology, Department of Veterinary and Biomedical Science, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Istvan Albert
- Center for Molecular Immunology and Infectious Disease, Department of Biochemistry and Molecular Biology, Department of Veterinary and Biomedical Science, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Laura T. Rust
- Center for Molecular Immunology and Infectious Disease, Department of Biochemistry and Molecular Biology, Department of Veterinary and Biomedical Science, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Victoria Holden
- Center for Molecular Immunology and Infectious Disease, Department of Biochemistry and Molecular Biology, Department of Veterinary and Biomedical Science, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Margherita T. Cantorna
- Center for Molecular Immunology and Infectious Disease, Department of Biochemistry and Molecular Biology, Department of Veterinary and Biomedical Science, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- * E-mail:
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804
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Diaz-Ochoa VE, Jellbauer S, Klaus S, Raffatellu M. Transition metal ions at the crossroads of mucosal immunity and microbial pathogenesis. Front Cell Infect Microbiol 2014; 4:2. [PMID: 24478990 PMCID: PMC3900919 DOI: 10.3389/fcimb.2014.00002] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 01/04/2014] [Indexed: 12/21/2022] Open
Abstract
Transition metal ions are essential micronutrients for all living organisms. In mammals, these ions are often protein-bound and sequestered within cells, limiting their availability to microbes. Moreover, in response to infection, mammalian hosts further reduce the availability of metal nutrients by activating epithelial cells and recruiting neutrophils, both of which release metal-binding proteins with antimicrobial function. Microorganisms, in turn, have evolved sophisticated systems to overcome these limitations and acquire the metal ions essential for their growth. Here we review some of the mechanisms employed by the host and by pathogenic microorganisms to compete for transition metal ions, with a discussion of how evading “nutritional immunity” benefits pathogens. Furthermore, we provide new insights on the mechanisms of host-microbe competition for metal ions in the mucosa, particularly in the inflamed gut.
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Affiliation(s)
- Vladimir E Diaz-Ochoa
- Department of Microbiology and Molecular Genetics, University of California, Irvine Irvine, CA, USA ; Institute for Immunology, University of California, Irvine Irvine, CA, USA
| | - Stefan Jellbauer
- Department of Microbiology and Molecular Genetics, University of California, Irvine Irvine, CA, USA ; Institute for Immunology, University of California, Irvine Irvine, CA, USA
| | - Suzi Klaus
- Department of Microbiology and Molecular Genetics, University of California, Irvine Irvine, CA, USA ; Institute for Immunology, University of California, Irvine Irvine, CA, USA
| | - Manuela Raffatellu
- Department of Microbiology and Molecular Genetics, University of California, Irvine Irvine, CA, USA ; Institute for Immunology, University of California, Irvine Irvine, CA, USA
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805
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Robinson CM, Jesudhasan PR, Pfeiffer JK. Bacterial lipopolysaccharide binding enhances virion stability and promotes environmental fitness of an enteric virus. Cell Host Microbe 2014; 15:36-46. [PMID: 24439896 PMCID: PMC3920179 DOI: 10.1016/j.chom.2013.12.004] [Citation(s) in RCA: 217] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 11/02/2013] [Accepted: 12/11/2013] [Indexed: 02/08/2023]
Abstract
Enteric viruses, including poliovirus and reovirus, encounter a vast microbial community in the mammalian gastrointestinal tract, which has been shown to promote virus replication and pathogenesis. Investigating the underlying mechanisms, we find that poliovirus binds bacterial surface polysaccharides, which enhances virion stability and cell attachment by increasing binding to the viral receptor. Additionally, we identified a poliovirus mutant, VP1-T99K, with reduced lipopolysaccharide (LPS) binding. Although T99K and WT poliovirus cell attachment, replication, and pathogenesis in mice are equivalent, VP1-T99K poliovirus was unstable in feces following peroral inoculation of mice. Consequently, the ratio of mutant virus in feces is reduced following additional cycles of infection in mice. Thus, the mutant virus incurs a fitness cost when environmental stability is a factor. These data suggest that poliovirus binds bacterial surface polysaccharides, enhancing cell attachment and environmental stability, potentially promoting transmission to a new host.
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Affiliation(s)
- Christopher M Robinson
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Palmy R Jesudhasan
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Julie K Pfeiffer
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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806
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Bern EM, Bousvaros A. Loss of response to biologics versus increased risk of lymphoma in children with inflammatory bowel disease: the clinician’s conundrum. Expert Rev Clin Immunol 2014; 9:117-27. [DOI: 10.1586/eci.12.97] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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807
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Lu DG, Ji XQ, Liu X, Li HJ, Zhang CQ. Pulmonary manifestations of Crohn’s disease. World J Gastroenterol 2014; 20:133-141. [PMID: 24415866 PMCID: PMC3886002 DOI: 10.3748/wjg.v20.i1.133] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 11/09/2013] [Accepted: 12/06/2013] [Indexed: 02/06/2023] Open
Abstract
Crohn’s disease (CD) is a systemic illness with a constellation of extraintestinal manifestations affecting various organs. Of these extraintestinal manifestations of CD, those involving the lung are relatively rare. However, there is a wide array of lung manifestations, ranging from subclinical alterations, airway diseases and lung parenchymal diseases to pleural diseases and drug-related diseases. The most frequent manifestation is bronchial inflammation and suppuration with or without bronchiectasis. Bronchoalveolar lavage findings show an increased percentage of neutrophils. Drug-related pulmonary abnormalities include disorders which are directly induced by sulfasalazine, mesalamine and methotrexate, and opportunistic lung infections due to immunosuppressive treatment. In most patients, the development of pulmonary disease parallels that of intestinal disease activity. Although infrequent, clinicians dealing with CD must be aware of these, sometimes life-threatening, conditions to avoid further impairment of health status and to alleviate patient symptoms by prompt recognition and treatment. The treatment of CD-related respiratory disorders depends on the specific pattern of involvement, and in most patients, steroids are required in the initial management.
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808
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Gómez-Moreno R, Robledo IE, Baerga-Ortiz A. Direct Detection and Quantification of Bacterial Genes Associated with Inflammation in DNA Isolated from Stool. ACTA ACUST UNITED AC 2014; 4:1065-1075. [PMID: 25635239 PMCID: PMC4307837 DOI: 10.4236/aim.2014.415117] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Although predominantly associated with health benefits, the gut microbiota has also been shown to harbor genes that promote inflammation. In this work, we report a method for the direct detection and quantification of these pro-inflammatory bacterial genes by PCR and qPCR in DNA extracted from human stool samples. PCR reactions were performed to detect (i) the pks island genes, (ii) tcpC, which is present in some strains of Escherichia coli and (iii) gelE presented in some strains of Enterococcus faecalis. Additionally, we screened for the presence of the following genes encoding cyclomodulins that disrupted mammalian cell division: (iv) cdt (which encodes the cytolethal distending toxin) and (v) cnf-1 (which encodes the cytotoxic necrotizing factor-1). Our results show that 20% of the samples (N = 41) tested positive for detectable amounts of pks island genes, whereas 10% of individuals were positive for tcpC or gelE and only one individual was found to harbor the cnf-1 gene. Of the 13 individuals that were positive for at least one of the pro-inflammatory genes, 5 were found to harbor more than one. A quantitative version of the assay, which used real-time PCR, revealed the pro-inflammatory genes to be in high copy numbers: up to 1.3 million copies per mg of feces for the pks island genes. Direct detection of specific genes in stool could prove useful toward screening for the presence of pro-inflammatory bacterial genes in individuals with inflammatory bowel diseases or colorectal cancer.
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Affiliation(s)
- Ramón Gómez-Moreno
- Department of Biochemistry, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico ; Molecular Sciences Building, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico
| | - Iraida E Robledo
- Department of Microbiology and Medical Zoology, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico
| | - Abel Baerga-Ortiz
- Department of Biochemistry, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico ; Molecular Sciences Building, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico
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809
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Stavely R, Sakkal S, Stojanovska V, Nurgali K. Mesenchymal stem cells for the treatment of inflammatory bowel disease: from experimental models to clinical application. Inflamm Regen 2014. [DOI: 10.2492/inflammregen.34.184] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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810
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Naughton J, Duggan G, Bourke B, Clyne M. Interaction of microbes with mucus and mucins: recent developments. Gut Microbes 2014; 5:48-52. [PMID: 24149677 PMCID: PMC4049936 DOI: 10.4161/gmic.26680] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Due to the recent rapid expansion in our understanding of the composition of the gut microflora and the consequences of altering that composition the question of how bacteria colonise mucus layers and interact with components of mucus, such as mucin, is now receiving widespread attention. Using a combination of mucus secreting cells, and a novel mucin microarray platform containing purified native mucins from different sources we recently demonstrated that two gastrointestinal pathogens, Helicobacter pylori and Campylobacter jejuni, colonise mucus by different mechanisms. This result emphasizes the potential for even closely related bacteria to interact with mucus in divergent ways to establish successful infection. Expanding the use of the mucin arrays described in the study to other microorganisms, both pathogenic and commensal, should lead to the discovery of biologically important motifs in bacterial-host interactions and complement the use of novel in vitro cell models, such as mucus secreting cell lines.
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Affiliation(s)
- Julie Naughton
- School of Medicine and Medical Science; University College Dublin; Dublin, Ireland,Conway Institute of Biomolecular and Biomedical Science; University College Dublin; Dublin, Ireland
| | - Gina Duggan
- School of Medicine and Medical Science; University College Dublin; Dublin, Ireland,Conway Institute of Biomolecular and Biomedical Science; University College Dublin; Dublin, Ireland
| | - Billy Bourke
- School of Medicine and Medical Science; University College Dublin; Dublin, Ireland,Conway Institute of Biomolecular and Biomedical Science; University College Dublin; Dublin, Ireland,National Children’s Research Centre; Our Lady’s Children’s Hospital; Dublin, Ireland
| | - Marguerite Clyne
- School of Medicine and Medical Science; University College Dublin; Dublin, Ireland,Conway Institute of Biomolecular and Biomedical Science; University College Dublin; Dublin, Ireland,Correspondence to: Marguerite Clyne,
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811
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Abstract
OBJECTIVES Crohn disease is characterized by chronic intestinal inflammation in the absence of a recognized etiology. Nutritional therapy in the form of exclusive enteral nutrition (EEN) has an established role within pediatric Crohn disease. Following exclusive enteral nutrition's success, many dietary therapies focusing on the elimination of specific complex carbohydrates have been anecdotally reported to be successful. METHODS Many of these therapies have not been evaluated scientifically; therefore, we reviewed the medical records of our patients with Crohn disease on the specific carbohydrate diet (SCD). RESULTS Seven children with Crohn disease receiving the SCD and no immunosuppressive medications were retrospectively evaluated. Duration of the dietary therapy ranged from 5 to 30 months, with an average of 14.6±10.8 months. Although the exact time of symptom resolution could not be determined through chart review, all symptoms were notably resolved at a routine clinic visit 3 months after initiating the diet. Each patient's laboratory indices, including serum albumin, C-reactive protein, hematocrit, and stool calprotectin, either normalized or significantly, improved during follow-up clinic visits. CONCLUSIONS This chart review suggests that the SCD and other low complex carbohydrate diets may be possible therapeutic options for pediatric Crohn disease. Further prospective studies are required to fully assess the safety and efficacy of the SCD, or any other low complex SCDs in pediatric patients with Crohn disease.
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812
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Inulin and Health Benefits. POLYSACCHARIDES 2014. [DOI: 10.1007/978-3-319-03751-6_37-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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813
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Fodor A. Utilizing “Omics” Tools to Study the Complex Gut Ecosystem. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 817:25-38. [DOI: 10.1007/978-1-4939-0897-4_2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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814
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Abstract
The colon serves as the habitat for trillions of microbes, which it must maintain, regulate, and sequester. This is managed by what is termed the mucosal barrier. The mucosal barrier separates the gut flora from the host tissues; regulates the absorption of water, electrolytes, minerals, and vitamins; and facilitates host-flora interactions. Colonic homeostasis depends on a complex interaction between the microflora and the mucosal epithelium, immune system, vasculature, stroma, and nervous system. Disruptions in the colonic microenvironment such as changes in microbial composition, epithelial cell function/proliferation/differentiation, mucus production/makeup, immune function, diet, motility, or blood flow may have substantial local and systemic consequences. Understanding the complex activities of the colon in health and disease is important in drug development, as xenobiotics can impact all segments of the colon. Direct and indirect effects of pharmaceuticals on intestinal function can produce adverse findings in laboratory animals and humans and can negatively impact drug development. This review will discuss normal colon homeostasis with examples, where applicable, of xenobiotics that disrupt normal function.
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Affiliation(s)
- Rani S Sellers
- 1Albert Einstein College of Medicine, Bronx, New York, USA
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815
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Alverdy J, Gilbert J, DeFazio JR, Sadowsky MJ, Chang EB, Morowitz MJ, Teitelbaum DH. Proceedings of the 2013 A.S.P.E.N. Research workshop: the interface between nutrition and the gut microbiome: implications and applications for human health [corrected]. JPEN J Parenter Enteral Nutr 2013; 38:167-78. [PMID: 24379111 DOI: 10.1177/0148607113517904] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The human and earth microbiomes are among the most important biological agents in understanding and preventing disease. Technology is advancing at a fast pace and allowing for high-resolution analysis of the composition and function of our microbial partners across regions, space, and time. Bioinformaticists and biostatisticians are developing ever more elegant displays to understand the generated megadatasets. A virtual cyberinfrastructure of search engines to cross-reference the rapidly developing data is emerging in line with technologic advances. Nutrition science will reap the benefits of this new field, and its role in preserving the earth and the humans who inhabit it will become evidently clear. In this report we highlight some of the topics of an A.S.P.E.N.-sponsored symposium held during Clinical Nutrition Week in 2013 that address the importance of the human microbiome to human health and disease.
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Affiliation(s)
- John Alverdy
- Department of Surgery, University of Chicago, Chicago, Illinois
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816
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Philpott DJ, Sorbara MT, Robertson SJ, Croitoru K, Girardin SE. NOD proteins: regulators of inflammation in health and disease. Nat Rev Immunol 2013; 14:9-23. [PMID: 24336102 DOI: 10.1038/nri3565] [Citation(s) in RCA: 462] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Entry of bacteria into host cells is an important virulence mechanism. Through peptidoglycan recognition, the nucleotide-binding oligomerization domain (NOD) proteins NOD1 and NOD2 enable detection of intracellular bacteria and promote their clearance through initiation of a pro-inflammatory transcriptional programme and other host defence pathways, including autophagy. Recent findings have expanded the scope of the cellular compartments monitored by NOD1 and NOD2 and have elucidated the signalling pathways that are triggered downstream of NOD activation. In vivo, NOD1 and NOD2 have complex roles, both during bacterial infection and at homeostasis. The association of alleles that encode constitutively active or constitutively inactive forms of NOD2 with different diseases highlights this complexity and indicates that a balanced level of NOD signalling is crucial for the maintenance of immune homeostasis.
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Affiliation(s)
- Dana J Philpott
- 1] Department of Immunology, University of Toronto, Toronto M5S 1A8, Canada. [2]
| | - Matthew T Sorbara
- 1] Department of Immunology, University of Toronto, Toronto M5S 1A8, Canada. [2]
| | | | - Kenneth Croitoru
- Institute of Medical Science, Department of Medicine, University of Toronto, Toronto M5S 1A8, Canada
| | - Stephen E Girardin
- 1] Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto M5S 1A8, Canada. [2]
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817
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818
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Carroll IM, Maharshak N. Enteric bacterial proteases in inflammatory bowel disease- pathophysiology and clinical implications. World J Gastroenterol 2013; 19:7531-7543. [PMID: 24431894 PMCID: PMC3837251 DOI: 10.3748/wjg.v19.i43.7531] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 10/05/2013] [Accepted: 11/05/2013] [Indexed: 02/06/2023] Open
Abstract
Numerous reports have identified a dysbiosis in the intestinal microbiota in patients suffering from inflammatory bowel diseases (IBD), yet the mechanism(s) in which this complex microbial community initiates or perpetuates inflammation remains unclear. The purpose of this review is to present evidence for one such mechanism that implicates enteric microbial derived proteases in the pathogenesis of IBD. We highlight and discuss studies demonstrating that proteases and protease receptors are abundant in the digestive system. Additionally, we investigate studies demonstrating an association between increased luminal protease activity and activation of protease receptors, ultimately resulting in increased intestinal permeability and exacerbation of colitis in animal models as well as in human IBD. Proteases are essential for the normal functioning of bacteria and in some cases can serve as virulence factors for pathogenic bacteria. Although not classified as traditional virulence factors, proteases originating from commensal enteric bacteria also have a potential association with intestinal inflammation via increased enteric permeability. Reports of increased protease activity in stools from IBD patients support a possible mechanism for a dysbiotic enteric microbiota in IBD. A better understanding of these pathways and characterization of the enteric bacteria involved, their proteases, and protease receptors may pave the way for new therapeutic approaches for these diseases.
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819
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Jex AR, Koehler AV, Ansell BR, Baker L, Karunajeewa H, Gasser RB. Getting to the guts of the matter: The status and potential of ‘omics’ research of parasitic protists of the human gastrointestinal system. Int J Parasitol 2013; 43:971-82. [DOI: 10.1016/j.ijpara.2013.06.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 06/07/2013] [Accepted: 06/07/2013] [Indexed: 11/17/2022]
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820
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Molecular signatures for the dynamic process of establishing intestinal host-microbial homeostasis: potential for disease diagnostics? Curr Opin Gastroenterol 2013; 29:621-7. [PMID: 24100720 DOI: 10.1097/mog.0b013e328365d365] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE OF REVIEW The dynamic interplay of the intestinal microbiota and host has been the focus of many studies because of its impact on the health status in human life. Recent reports on the time-resolved immune and metabolic interactions between the host and microbiota, as well as the molecular signatures that mark this communication during the process of establishing a host-microbial relationship, are addressed here. RECENT FINDINGS During microbial colonization, the progressive impact of de-novo introduction of the gut microbiota on the host's physiology is tightly controlled by highly intertwined regulatory networks and achieves an efficient and balanced interplay between the host and its developing microbial community. Recent findings from germ-free mouse models have unravelled core transcriptional, metabolic and microbial signatures, which are proposed to orchestrate the molecular responses during the establishment of the multifaceted state of intestinal host-microbe homeostasis. SUMMARY Exploring the time-resolved dynamics of the host responses to the newly colonizing gut microbiota provides mechanistically critical understanding of the sequential host-microbe response cascades that lead to a homeostatic relationship. Thereby, these approaches can provide novel diagnostic tools and therapeutic targets, or either of the two, in humans for specific disorders associated with intestinal dysbiosis and loss of homeostasis.
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821
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Abstract
BACKGROUND Profermin is developed for the dietary management of ulcerative colitis (UC). It consists of water, fermented oats, barley malt, lecithin, and Lactobacillus plantarum 299v. The aim of this study was to assess the clinical efficacy of Profermin. METHODS Seventy-four patients with a mild-to-moderate flare-up of UC (defined as Simple Clinical Colitis Activity Index [SCCAI] score ≥5 and ≤11) were randomly assigned to Profermin (n = 32) or Fresubin (n = 41). The primary endpoint was to assess whether addition of Profermin in UC could significantly reduce SCCAI in comparison with Fresubin. RESULTS In the run-in period, the mean SCCAI was 7.2 ± 1.50 in the Profermin group and 7.6 ± 1.47 in the Fresubin group (not significant). After 8 weeks of treatment, the mean reduction of SCCAI score was higher in the Profermin group (mean difference: -1.77 SCCAI, 95% confidence interval -2.97 to -0.55; P < 0.005), in intention-to-treat analyses. Remission defined as SCCAI ≤2.5 was achieved in 10 of 32 (31%) in the Profermin group and in 6 of 41 (15%) in the Fresubin group (P = 0.048). The decrease in SCCAI scores of ≥50% was higher in the Profermin group 17 of 32 (53%) versus 11 of 41 (27%) (P = 0.04). The risk of dropping out due to treatment failure/lack of effect was higher in the Fresubin group (42% versus 13%, P = 0.02). CONCLUSIONS Supplementation with Profermin is safe, well tolerated, palatable, and able to reduce SCCAI scores at a statistically and clinically significant level in patients with mild-to-moderate UC with a flare-up.
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822
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Moschen AR, Kaser S, Tilg H. Non-alcoholic steatohepatitis: a microbiota-driven disease. Trends Endocrinol Metab 2013; 24:537-45. [PMID: 23827477 DOI: 10.1016/j.tem.2013.05.009] [Citation(s) in RCA: 129] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2013] [Revised: 05/24/2013] [Accepted: 05/29/2013] [Indexed: 02/07/2023]
Abstract
Non-alcoholic fatty liver disease (NAFLD) has emerged as a major health problem worldwide. Whereas overnutrition and obesity are crucially involved in the development of a simple fatty liver, it remains unclear why approximately 10% of all affected individuals develop the 'inflammatory' phenotype so-called non-alcoholic steatohepatitis (NASH). A link between the intestinal microbiota and the development of obesity and its metabolic consequences including NAFLD is becoming clearer. First clinical, but especially experimental, studies are suggesting that microbiotal factors are driving forces of hepatic steatosis and inflammation that involve Toll-like receptors and proinflammatory cytokines such as tumor necrosis factor-α (TNFα). Future studies focused on deciphering how manipulation of the gut microbiota might prove beneficial for patients with NAFLD are warranted.
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Affiliation(s)
- Alexander R Moschen
- Department of Internal Medicine I, Endocrinology, Gastroenterology, and Metabolism, Medical University Innsbruck, Austria
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823
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Crost EH, Tailford LE, Le Gall G, Fons M, Henrissat B, Juge N. Utilisation of mucin glycans by the human gut symbiont Ruminococcus gnavus is strain-dependent. PLoS One 2013; 8:e76341. [PMID: 24204617 PMCID: PMC3808388 DOI: 10.1371/journal.pone.0076341] [Citation(s) in RCA: 211] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 08/22/2013] [Indexed: 12/24/2022] Open
Abstract
Commensal bacteria often have an especially rich source of glycan-degrading enzymes which allow them to utilize undigested carbohydrates from the food or the host. The species Ruminococcus gnavus is present in the digestive tract of ≥90% of humans and has been implicated in gut-related diseases such as inflammatory bowel diseases (IBD). Here we analysed the ability of two R. gnavus human strains, E1 and ATCC 29149, to utilize host glycans. We showed that although both strains could assimilate mucin monosaccharides, only R. gnavus ATCC 29149 was able to grow on mucin as a sole carbon source. Comparative genomic analysis of the two R. gnavus strains highlighted potential clusters and glycoside hydrolases (GHs) responsible for the breakdown and utilization of mucin-derived glycans. Transcriptomic and functional activity assays confirmed the importance of specific GH33 sialidase, and GH29 and GH95 fucosidases in the mucin utilisation pathway. Notably, we uncovered a novel pathway by which R. gnavus ATCC 29149 utilises sialic acid from sialylated substrates. Our results also demonstrated the ability of R. gnavus ATCC 29149 to produce propanol and propionate as the end products of metabolism when grown on mucin and fucosylated glycans. These new findings provide molecular insights into the strain-specificity of R. gnavus adaptation to the gut environment advancing our understanding of the role of gut commensals in health and disease.
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Affiliation(s)
- Emmanuelle H. Crost
- The Gut Health and Food Safety Institute Strategic Programme, Institute of Food Research, Norwich, United Kingdom
| | - Louise E. Tailford
- The Gut Health and Food Safety Institute Strategic Programme, Institute of Food Research, Norwich, United Kingdom
| | - Gwenaelle Le Gall
- The Gut Health and Food Safety Institute Strategic Programme, Institute of Food Research, Norwich, United Kingdom
| | - Michel Fons
- Laboratoire de Chimie Bactérienne, Institut de Microbiologie de la Méditerranée, CNRS and Aix-Marseille University, Marseille, France
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques, CNRS and Aix-Marseille University, Marseille, France
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nathalie Juge
- The Gut Health and Food Safety Institute Strategic Programme, Institute of Food Research, Norwich, United Kingdom
- * E-mail:
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824
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Sunagawa S, Mende DR, Zeller G, Izquierdo-Carrasco F, Berger SA, Kultima JR, Coelho LP, Arumugam M, Tap J, Nielsen HB, Rasmussen S, Brunak S, Pedersen O, Guarner F, de Vos WM, Wang J, Li J, Doré J, Ehrlich SD, Stamatakis A, Bork P. Metagenomic species profiling using universal phylogenetic marker genes. Nat Methods 2013; 10:1196-9. [PMID: 24141494 DOI: 10.1038/nmeth.2693] [Citation(s) in RCA: 327] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 09/24/2013] [Indexed: 12/11/2022]
Abstract
To quantify known and unknown microorganisms at species-level resolution using shotgun sequencing data, we developed a method that establishes metagenomic operational taxonomic units (mOTUs) based on single-copy phylogenetic marker genes. Applied to 252 human fecal samples, the method revealed that on average 43% of the species abundance and 58% of the richness cannot be captured by current reference genome-based methods. An implementation of the method is available at http://www.bork.embl.de/software/mOTU/.
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825
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Ringel Y, Maharshak N. Intestinal microbiota and immune function in the pathogenesis of irritable bowel syndrome. Am J Physiol Gastrointest Liver Physiol 2013; 305:G529-41. [PMID: 23886861 PMCID: PMC3798736 DOI: 10.1152/ajpgi.00207.2012] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 07/17/2013] [Indexed: 02/08/2023]
Abstract
The pathophysiology of irritable bowel syndrome (IBS) is believed to involve alterations in the brain-gut axis; however, the etiological triggers and mechanisms by which these changes lead to symptoms of IBS remain poorly understood. Although IBS is often considered a condition without an identified "organic" etiology, emerging evidence suggests that alterations in the gastrointestinal microbiota and altered immune function may play a role in the pathogenesis of the disorder. These recent data suggest a plausible model in which changes in the intestinal microbiota and activation of the enteric immune system may impinge upon the brain-gut axis, causing the alterations in gastrointestinal function and the clinical symptoms observed in patients with IBS. This review summarizes the current evidence for altered intestinal microbiota and immune function in IBS. It discusses the potential etiological role of these factors, suggests an updated conceptual model for the pathogenesis of the disorder, and identifies areas for future research.
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Affiliation(s)
- Yehuda Ringel
- Division of Gastroenterology and Hepatology, Univ. of North Carolina at Chapel Hill School of Medicine, 4107 BioInformatics Bldg., CB# 7080, 130 Mason Farm Rd., Chapel Hill, NC 27599-7080.
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826
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Arthur JC, Gharaibeh RZ, Uronis JM, Perez-Chanona E, Sha W, Tomkovich S, Mühlbauer M, Fodor AA, Jobin C. VSL#3 probiotic modifies mucosal microbial composition but does not reduce colitis-associated colorectal cancer. Sci Rep 2013; 3:2868. [PMID: 24100376 PMCID: PMC3792409 DOI: 10.1038/srep02868] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Accepted: 09/18/2013] [Indexed: 02/07/2023] Open
Abstract
Although probiotics have shown success in preventing the development of experimental colitis-associated colorectal cancer (CRC), beneficial effects of interventional treatment are relatively unknown. Here we show that interventional treatment with VSL#3 probiotic alters the luminal and mucosally-adherent microbiota, but does not protect against inflammation or tumorigenesis in the azoxymethane (AOM)/Il10⁻/⁻ mouse model of colitis-associated CRC. VSL#3 (10⁹ CFU/animal/day) significantly enhanced tumor penetrance, multiplicity, histologic dysplasia scores, and adenocarcinoma invasion relative to VSL#3-untreated mice. Illumina 16S sequencing demonstrated that VSL#3 significantly decreased (16-fold) the abundance of a bacterial taxon assigned to genus Clostridium in the mucosally-adherent microbiota. Mediation analysis by linear models suggested that this taxon was a contributing factor to increased tumorigenesis in VSL#3-fed mice. We conclude that VSL#3 interventional therapy can alter microbial community composition and enhance tumorigenesis in the AOM/Il10⁻/⁻ model.
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Affiliation(s)
| | - Raad Z. Gharaibeh
- Bioinformatics Services Division, Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Kannapolis, NC 28081, USA
| | | | | | - Wei Sha
- Bioinformatics Services Division, Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Kannapolis, NC 28081, USA
| | - Sarah Tomkovich
- Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | | | - Anthony A. Fodor
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Christian Jobin
- Department of Medicine, Chapel Hill, NC 27599, USA
- Pharmacology, Chapel Hill, NC 27599, USA
- Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Department of Medicine, University of Florida at Gainesville, Gainesville, FL32611, USA
- Department of Infectious Diseases and Pathology, University of Florida at Gainesville, Gainesville, FL32611, USA
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827
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Abstract
In recent years investigations of inflammatory bowel disease (IBD) have advanced rapidly with regard to the relationship between the host immune response and gut microbiota. Patients with IBD have been shown to have an abnormal composition of gut microbiota and host immune dysregulation. Abnormal components of gut microbiota, to which the host mounts aberrant immune responses in genetically vulnerable individuals, appear to play a critical role in the pathogenesis of IBD. Therefore, inappropriate innate and adaptive host immune responses to abnormal components of gut microbiota and their products form the basis of IBD pathogenesis. Modern molecular genetic methods should be utilized to help to illuminate the pathogenetic mechanism of IBD and to develop personalized therapeutic strategies for this disease.
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Affiliation(s)
- Cheng Gong Yu
- Department of Gastroenterology, Nanjing Drum Tower Hospital, Affiliated Hospital of Nanjing University Medical School, Jiangsu Province, China
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828
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Trivedi PJ, Adams DH. Mucosal immunity in liver autoimmunity: A comprehensive review. J Autoimmun 2013; 46:97-111. [DOI: 10.1016/j.jaut.2013.06.013] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 06/19/2013] [Indexed: 12/14/2022]
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829
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Yang T, Owen JL, Lightfoot YL, Kladde MP, Mohamadzadeh M. Microbiota impact on the epigenetic regulation of colorectal cancer. Trends Mol Med 2013; 19:714-25. [PMID: 24051204 DOI: 10.1016/j.molmed.2013.08.005] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 08/02/2013] [Accepted: 08/22/2013] [Indexed: 12/12/2022]
Abstract
Mechanisms of colorectal cancer (CRC) development can be generally divided into three categories: genetic, epigenetic, and aberrant immunologic signaling pathways, all of which may be triggered by an imbalanced intestinal microbiota. Aberrant gut microbial composition, termed 'dysbiosis', has been reported in inflammatory bowel disease patients who are at increased risk for CRC development. Recent studies indicate that it is feasible to rescue experimental models of colonic cancer by oral treatment with genetically engineered beneficial bacteria and/or their immune-regulating gene products. Here, we review the mechanisms of epigenetic modulation implicated in the development and progression of CRC, which may be the result of dysbiosis, and therefore may be amenable to therapeutic intervention.
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Affiliation(s)
- Tao Yang
- Department of Infectious Diseases and Pathology, University of Florida, Gainesville, FL 32608 USA; Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Florida, Gainesville, FL 32610 USA
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830
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Role of diet and gut microbiota in management of inflammatory bowel disease in an Asian migrant. J Allergy Clin Immunol 2013; 132:250-250.e5. [PMID: 23810100 DOI: 10.1016/j.jaci.2013.05.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 05/22/2013] [Accepted: 05/24/2013] [Indexed: 12/19/2022]
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831
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Alteration of intestinal dysbiosis by fecal microbiota transplantation does not induce remission in patients with chronic active ulcerative colitis. Inflamm Bowel Dis 2013; 19:2155-65. [PMID: 23899544 DOI: 10.1097/mib.0b013e31829ea325] [Citation(s) in RCA: 186] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND In patients with ulcerative colitis (UC), alterations of the intestinal microbiota, termed dysbiosis, have been postulated to contribute to intestinal inflammation. Fecal microbiota transplantation (FMT) has been used as effective therapy for recurrent Clostridium difficile colitis also caused by dysbiosis. The aims of the present study were to investigate if patients with UC benefit from FMT and if dysbiosis can be reversed. METHODS Six patients with chronic active UC nonresponsive to standard medical therapy were treated with FMT by colonoscopic administration. Changes in the colonic microbiota were assessed by 16S rDNA-based microbial community profiling using high-throughput pyrosequencing from mucosal and stool samples. RESULTS All patients experienced short-term clinical improvement within the first 2 weeks after FMT. However, none of the patients achieved clinical remission. Microbiota profiling showed differences in the modification of the intestinal microbiota between individual patients after FMT. In 3 patients, the colonic microbiota changed toward the donor microbiota; however, this did not correlate with clinical response. On phylum level, there was a significant reduction of Proteobacteria and an increase in Bacteroidetes after FMT. CONCLUSIONS FMT by a single colonoscopic donor stool application is not effective in inducing remission in chronic active therapy-refractory UC. Changes in the composition of the intestinal microbiota were significant and resulted in a partial improvement of UC-associated dysbiosis. The results suggest that dysbiosis in UC is at least in part a secondary phenomenon induced by inflammation and diarrhea rather than being causative for inflammation in this disease.
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832
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Packey CD, Shanahan MT, Manick S, Bower MA, Ellermann M, Tonkonogy SL, Carroll IM, Sartor RB. Molecular detection of bacterial contamination in gnotobiotic rodent units. Gut Microbes 2013; 4:361-70. [PMID: 23887190 PMCID: PMC3839980 DOI: 10.4161/gmic.25824] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Gnotobiotic rodents provide an important technique to study the functional roles of commensal bacteria in host physiology and pathophysiology. To ensure sterility, these animals must be screened frequently for contamination. The traditional screening approaches of culturing and Gram staining feces have inherent limitations, as many bacteria are uncultivable and fecal Gram stains are difficult to interpret. Thus, we developed and validated molecular methods to definitively detect and identify contamination in germ-free (GF) and selectively colonized animals. Fresh fecal pellets were collected from rodents housed in GF isolators, spontaneously contaminated ex-GF isolators, selectively colonized isolators and specific pathogen-free (SPF) conditions. DNA isolated from mouse and rat fecal samples was amplified by polymerase chain reaction (PCR) and subjected to quantitative PCR (qPCR) using universal primers that amplify the 16S rRNA gene from all bacterial groups. PCR products were sequenced to identify contaminating bacterial species. Random amplification of polymorphic DNA (RAPD) PCR profiles verified bacterial inoculation of selectively colonized animals. These PCR techniques more accurately detected and identified GF isolator contamination than current standard approaches. These molecular techniques can be utilized to more definitively screen GF and selectively colonized animals for bacterial contamination when Gram stain and/or culture results are un-interpretable or inconsistent.
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Affiliation(s)
- Christopher D Packey
- Department of Medicine; University of North Carolina at Chapel Hill; Chapel Hill, NC USA,Department of Microbiology and Immunology; University of North Carolina at Chapel Hill; Chapel Hill, NC USA,Center for Gastrointestinal Biology and Diseases; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
| | - Michael T Shanahan
- Department of Medicine; University of North Carolina at Chapel Hill; Chapel Hill, NC USA,Center for Gastrointestinal Biology and Diseases; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
| | - Sayeed Manick
- Department of Medicine; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
| | - Maureen A Bower
- The National Gnotobiotic Rodent Resource Center; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
| | - Melissa Ellermann
- Department of Microbiology and Immunology; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
| | - Susan L Tonkonogy
- Center for Gastrointestinal Biology and Diseases; University of North Carolina at Chapel Hill; Chapel Hill, NC USA,College of Veterinary Medicine, North Carolina State University; Raleigh, NC USA
| | - Ian M Carroll
- Department of Medicine; University of North Carolina at Chapel Hill; Chapel Hill, NC USA,Center for Gastrointestinal Biology and Diseases; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
| | - R Balfour Sartor
- Department of Medicine; University of North Carolina at Chapel Hill; Chapel Hill, NC USA,Department of Microbiology and Immunology; University of North Carolina at Chapel Hill; Chapel Hill, NC USA,Center for Gastrointestinal Biology and Diseases; University of North Carolina at Chapel Hill; Chapel Hill, NC USA,The National Gnotobiotic Rodent Resource Center; University of North Carolina at Chapel Hill; Chapel Hill, NC USA,Correspondence to: R Balfour Sartor,
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833
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Impact of ileocecal resection and concomitant antibiotics on the microbiome of the murine jejunum and colon. PLoS One 2013; 8:e73140. [PMID: 24015295 PMCID: PMC3754918 DOI: 10.1371/journal.pone.0073140] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Accepted: 07/17/2013] [Indexed: 02/07/2023] Open
Abstract
Ileocecal resection (ICR) is a commonly required surgical intervention in unmanageable Crohn's disease and necrotizing enterocolitis. However, the impact of ICR, and the concomitant doses of antibiotic routinely given with ICR, on the intestinal commensal microbiota has not been determined. In this study, wild-type C57BL6 mice were subjected to ICR and concomitant single intraperitoneal antibiotic injection. Intestinal lumen contents were collected from jejunum and colon at 7, 14, and 28 days after resection and compared to non-ICR controls. Samples were analyzed by 16S rRNA gene pyrosequencing and quantitative PCR. The intestinal microbiota was altered by 7 days after ICR and accompanying antibiotic treatment, with decreased diversity in the colon. Phylogenetic diversity (PD) decreased from 11.8 ± 1.8 in non-ICR controls to 5.9 ± 0.5 in 7-day post-ICR samples. There were also minor effects in the jejunum where PD values decreased from 8.3 ± 0.4 to 7.5 ± 1.4. PCoA analysis indicated that bacterial populations 28 days post-ICR differed significantly from non-ICR controls. Moreover, colon and jejunum bacterial populations were remarkably similar 28 days after resection, whereas the initial communities differed markedly. Firmicutes and Bacteroidetes were the predominant phyla in jejunum and colon before ICR; however, Firmicutes became the vastly predominant phylum in jejunum and colon 28 days after ICR. Although the microbiota returned towards a homeostatic state, with re-establishment of Firmicutes as the predominant phylum, we did not detect Bacteroidetes in the colon 28 days after ICR. In the jejunum Bacteroidetes was detected at a 0.01% abundance after this time period. The changes in jejunal and colonic microbiota induced by ICR and concomitant antibiotic injection may therefore be considered as potential regulators of post-surgical adaptive growth or function, and in a setting of active IBD, potential contributors to post-surgical pathophysiology of disease recurrence.
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834
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Gut microbial flora, prebiotics, and probiotics in IBD: their current usage and utility. BIOMED RESEARCH INTERNATIONAL 2013; 2013:435268. [PMID: 23991417 PMCID: PMC3749555 DOI: 10.1155/2013/435268] [Citation(s) in RCA: 127] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 06/29/2013] [Accepted: 07/08/2013] [Indexed: 12/12/2022]
Abstract
Inflammatory bowel diseases are chronic diseases affecting the gastrointestinal tract, whose major forms are represented by Crohn's disease (CD) and ulcerative colitis (UC). Their etiology is still unclear, although several factors have been identified as major determinants for induction or relapses. Among these, the role of the "forgotten organ", gut microbiota, has become more appreciated in recent years. The delicate symbiotic relationship between the gut microbiota and the host appears to be lost in IBD. In this perspective, several studies have been conducted to assess the role of prebiotics and probiotics in gut microbiota modulation. This is a minireview aimed to address in an easy format (simple questions-simple answers) some common issues about the theme. An update on the role of selected constituents of gut microbiota in the pathogenesis of IBD is presented together with the analysis of the efficacy of gut microbiota modulation by prebiotics and probiotics administration in the management of IBD.
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835
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Magrone T, Jirillo E. The interaction between gut microbiota and age-related changes in immune function and inflammation. IMMUNITY & AGEING 2013; 10:31. [PMID: 23915308 PMCID: PMC3848811 DOI: 10.1186/1742-4933-10-31] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Accepted: 05/10/2013] [Indexed: 02/07/2023]
Abstract
Intestinal microbiota and gut immune systems interact each other, maintaining a condition of homeostasis in the context of the intestinal habitat. However, both systems undergo modifications in elderly, thus accounting for a low grade inflammatory status which, in turn, may evolve toward more severe pathological conditions such as inflammatory bowel disease and colon rectal cancer. In addition, in western societies dietary habits may negatively influence the microbiota composition, also altering gut immune response which is per se impaired in elderly. In order to prevent the outcome of aged-related disease, supplementation of nutraceuticals able to correct abnormalities of both immune system and microbiota has become more frequent than in the past. In this respect, a better identification of components of the aged microbiota as well as a deeper analysis of gut mucosal immunity function should be pursued.
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Affiliation(s)
- Thea Magrone
- Department of Basic Medical Sciences, Neuroscience and Sensory Organs, University of Bari, Policlinico, Piazza G, Cesare 11, 70124, Bari, Italy.
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836
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Di Luccia B, Manzo N, Baccigalupi L, Calabrò V, Crescenzi E, Ricca E, Pollice A. Lactobacillus gasseri SF1183 affects intestinal epithelial cell survival and growth. PLoS One 2013. [PMID: 23894414 DOI: 10.1016/j.jff.2017.12.049] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
It is now commonly accepted that the intestinal microbiota plays a crucial role in the gut physiology and homeostasis, and that both qualitative and quantitative alterations in the compositions of the gut flora exert profound effects on the host's intestinal cells. In spite of this, the details of the interaction between commensal bacteria and intestinal cells are still largely unknown and only in few cases the molecular mechanisms have been elucidated. Here we analyze the effects of molecules produced and secreted by Lactobacillus gasseri SF1183 on human intestinal HCT116 cells. L. gasseri is a well known species of lactic acid bacteria, commonly associated to the human intestine and SF1183 is a human strain previously isolated from an ileal biopsy of an healthy volunteer. SF1183 produces and secretes, in a growth phase-dependent way, molecule(s) able to drastically interfere with HCT116 cell proliferation. Although several attempts to purify and identify the bioactive molecule(s) have been so far unsuccessful, a partial characterization has indicated that it is smaller than 3 kDa, thermostable and of proteinaceous nature. L. gasseri molecule(s) stimulate a G1-phase arrest of the cell cycle by up-regulation of p21WAF1 rendering cells protected from intrinsic and extrinsic apoptosis. A L. gasseri-mediated reduction of apoptosis and of cell proliferation could be relevant in protecting epithelial barrier integrity and helping in reconstituting tissutal homeostasis.
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Affiliation(s)
- Blanda Di Luccia
- Department of Biology, University of Naples Federico II-MSA-Via Cinthia, Naples, Italy
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837
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Huang EY, Devkota S, Moscoso D, Chang EB, Leone VA. The role of diet in triggering human inflammatory disorders in the modern age. Microbes Infect 2013; 15:765-74. [PMID: 23876436 DOI: 10.1016/j.micinf.2013.07.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 07/12/2013] [Indexed: 12/11/2022]
Abstract
Previously uncommon human inflammatory disorders are emerging with alarming frequency, possibly triggered by environmental factors introduced through Westernization. This review highlights how Western diets heighten the inflammatory state promoting development of disease. Evidence that this can occur directly or indirectly through perturbations of host-microbe interactions are reviewed.
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Affiliation(s)
- Edmond Y Huang
- Department of Medicine, University of Chicago, 900 East 57th Street, Chicago, IL 60637, USA.
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838
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Adamu BO, Lawley TD. Bacteriotherapy for the treatment of intestinal dysbiosis caused by Clostridium difficile infection. Curr Opin Microbiol 2013; 16:596-601. [PMID: 23866975 PMCID: PMC3840269 DOI: 10.1016/j.mib.2013.06.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Accepted: 06/25/2013] [Indexed: 12/21/2022]
Abstract
Antibiotics damage the intestinal microbiota and disrupt colonization resistance predisposing us to recurrent C. difficile infection (CDI). Faecal microbiota transplantation (FMT) is a promising treatment for recurrent C. difficile infection. Mixtures of beneficial bacteria known as bacteriotherapy should be developed for treatment of CDI and other diseases linked to dysbiosis in the intestinal microbiota.
Faecal microbiota transplantation (FMT) has been used for more than five decades to treat a variety of intestinal diseases associated with pathological imbalances within the resident microbiota, termed dysbiosis. FMT has been particularly effective for treating patients with recurrent Clostridium difficile infection who are left with few clinical options other than continued antibiotic therapy. Our increasing knowledge of the structure and function of the human intestinal microbiota and C. difficile pathogenesis has led to the understanding that FMT promotes intestinal ecological restoration and highlights the microbiota as a viable therapeutic target. However, the use of undefined faecal samples creates a barrier for widespread clinical use because of safety and aesthetic issues. An emerging concept of bacteriotherapy, the therapeutic use of a defined mixture of harmless, health-associated bacteria, holds promise for the treatment of patients with severe C. difficile infection, and possibly represents a paradigm shift for the treatment of diseases linked to intestinal dysbiosis.
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839
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Normand S, Secher T, Chamaillard M. La dysbiose, une nouvelle entité en médecine ? Med Sci (Paris) 2013; 29:586-9. [DOI: 10.1051/medsci/2013296011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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840
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Coskun M, Salem M, Pedersen J, Nielsen OH. Involvement of JAK/STAT signaling in the pathogenesis of inflammatory bowel disease. Pharmacol Res 2013; 76:1-8. [PMID: 23827161 DOI: 10.1016/j.phrs.2013.06.007] [Citation(s) in RCA: 227] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Revised: 06/06/2013] [Accepted: 06/18/2013] [Indexed: 02/07/2023]
Abstract
The Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway constitute the fulcrum in many vital cellular processes, including cell growth, differentiation, proliferation, and regulatory immune functions. Various cytokines, growth factors, and protein tyrosine kinases communicate through the JAK/STAT pathway and regulate the transcription of numerous genes. In addition to their critical roles in a plethora of key cellular activities, the JAK/STAT signaling pathways also have been implicated in the pathogenesis of several diseases, including inflammatory bowel disease (IBD), especially since a JAK inhibitor recently has been shown to be effective in the treatment of ulcerative colitis. The aim of this review is to highlight the recent findings on the regulatory mechanism of JAK/STAT signaling pathways and to reveal the evolving comprehension of their interface which might be of interest for clinicians involved in IBD therapy. Further, it is described how these signaling pathways have been exploited for the development of promising novel JAK inhibitors with anti-inflammatory effects verified in clinical trials.
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Affiliation(s)
- Mehmet Coskun
- Department of Gastroenterology, Medical Section, Herlev Hospital, University of Copenhagen, Denmark.
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841
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Abstract
The gut flora is composed of a huge number of diverse, well-adapted symbionts that interact with epithelial lining throughout the host's entire life. Not all commensals have the same ability to maintain quiescent, protective inflammation. Importantly, instability in the composition of gut microbial communities (referred to as dysbiosis) has been linked to loss of gut barrier in the context of common human illnesses with increasing socio-economic impacts, such as Crohn disease and colorectal cancer. Our recent findings suggest that disease-predisposing dysbiosis can now be intentionally manipulated by targeting the major Crohn disease-predisposing NOD2 gene. That knowledge will not only add a new dimension to the often overlooked microbiology of Crohn disease and colorectal cancer, but will also have a broad impact on biomedical sciences worldwide.
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Affiliation(s)
- Thomas Secher
- INRA; Institut National de la Santé et de la Recherche Médicale; UMR 1043; Toulouse, France
| | - Sylvain Normand
- University Lille Nord de France; Lille, France,Institut Pasteur de Lille; Center for Infection and Immunity of Lille; Lille, France,Centre National de la Recherche Scientifique; Unité Mixte de Recherche 8204; Lille, France,Institut National de la Santé et de la Recherche Médicale; U1019; Lille, France
| | - Mathias Chamaillard
- University Lille Nord de France; Lille, France,Institut Pasteur de Lille; Center for Infection and Immunity of Lille; Lille, France,Centre National de la Recherche Scientifique; Unité Mixte de Recherche 8204; Lille, France,Institut National de la Santé et de la Recherche Médicale; U1019; Lille, France,Correspondence to: Mathias Chamaillard,
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842
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Guinane CM, Cotter PD. Role of the gut microbiota in health and chronic gastrointestinal disease: understanding a hidden metabolic organ. Therap Adv Gastroenterol 2013; 6:295-308. [PMID: 23814609 PMCID: PMC3667473 DOI: 10.1177/1756283x13482996] [Citation(s) in RCA: 477] [Impact Index Per Article: 43.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The human gut microbiota has become the subject of extensive research in recent years and our knowledge of the resident species and their potential functional capacity is rapidly growing. Our gut harbours a complex community of over 100 trillion microbial cells which influence human physiology, metabolism, nutrition and immune function while disruption to the gut microbiota has been linked with gastrointestinal conditions such as inflammatory bowel disease and obesity. Here, we review the many significant recent studies that have centred on further enhancing our understanding of the complexity of intestinal communities as well as their genetic and metabolic potential. These have provided important information with respect to what constitutes a 'healthy gut microbiota' while furthering our understanding of the role of gut microbes in intestinal diseases. We also highlight recently developed genomic and other tools that are used to study the gut microbiome and, finally, we consider the manipulation of the gut microbiota as a potential therapeutic option to treat chronic gastrointestinal disease.
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Affiliation(s)
| | - Paul D. Cotter
- Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland The Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
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843
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Rigottier-Gois L. Dysbiosis in inflammatory bowel diseases: the oxygen hypothesis. THE ISME JOURNAL 2013; 7:1256-61. [PMID: 23677008 PMCID: PMC3695303 DOI: 10.1038/ismej.2013.80] [Citation(s) in RCA: 270] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2013] [Revised: 03/17/2013] [Accepted: 04/13/2013] [Indexed: 12/13/2022]
Abstract
The healthy intestine is characterized by a low level of oxygen and by the presence of large bacterial communities of obligate anaerobes. Dysbiosis of the gut microbiota has been reported in patients suffering from inflammatory bowel diseases (IBDs), but the mechanisms causing this imbalance remain unknown. Observations have included a decrease in obligate anaerobes of the phylum Firmicutes and an increase in facultative anaerobes, including members of the family Enterobacteriaceae. The shift of bacterial communities from obligate to facultative anaerobes strongly suggests a disruption in anaerobiosis and points to a role for oxygen in intestinal dysbiosis. Proposals to evaluate this hypothesis of a role for oxygen in IBD dysbiosis are provided. If this hypothesis is confirmed, decreasing oxygen in the intestine could open novel means to rebalance the microbiota and could provide novel preventative or therapeutic strategies for IBD patients in whom current treatments are ineffective.
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844
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Schaeverbeke T, Truchetet ME, Richez C. Gut metagenome and spondyloarthritis. Joint Bone Spine 2013; 80:349-52. [PMID: 23806346 DOI: 10.1016/j.jbspin.2013.02.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/04/2013] [Indexed: 02/07/2023]
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845
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McCabe LR, Irwin R, Schaefer L, Britton RA. Probiotic use decreases intestinal inflammation and increases bone density in healthy male but not female mice. J Cell Physiol 2013; 228:1793-8. [PMID: 23389860 DOI: 10.1002/jcp.24340] [Citation(s) in RCA: 188] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 01/28/2013] [Indexed: 12/31/2022]
Abstract
Osteoporosis can result from intestinal inflammation, as is seen with inflammatory bowel disease. Probiotics, microorganisms that provide a health benefit to the host when ingested in adequate amounts, can have anti-inflammatory properties and are currently being examined to treat inflammatory bowel disease. Here, we examined if treating healthy male mice with Lactobacillus reuteri ATCC PTA 6475 (a candidate probiotic with anti-TNFα activity) could affect intestinal TNFα levels and enhance bone density. Adult male mice were given L. reuteri 6475 orally by gavage for 3×/week for 4 weeks. Examination of jejunal and ileal RNA profiles indicates that L. reuteri suppressed basal TNFα mRNA levels in the jejunum and ileum in male mice, but surprisingly not in female mice. Next, we examined bone responses. Micro-computed tomography demonstrated that L. reuteri 6475 treatment increased male trabecular bone parameters (mineral density, bone volume fraction, trabecular number, and trabecular thickness) in the distal femur metaphyseal region as well as in the lumbar vertebrae. Cortical bone parameters were unaffected. Dynamic and static histomorphometry and serum remodeling parameters indicate that L. reuteri ingestion increases osteoblast serum markers and dynamic measures of bone formation in male mice. In contrast to male mice, L. reuteri had no effect on bone parameters in female mice. Taken together our studies indicate that femoral and vertebral bone formation increases in response to oral probiotic use, leading to increased trabecular bone volume in male mice.
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Affiliation(s)
- Laura R McCabe
- Department of Physiology, Michigan State University, East Lansing, Michigan 48824, USA.
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846
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Abstract
Mucin-type O-glycans are the primary constituents of mucins that are expressed on various mucosal sites of the body, especially the bacteria-laden intestinal tract. Mucins are the main components of mucus, which is secreted by goblet cells and forms a protective homeostatic barrier between the resident microbiota and the underlying immune cells in the colon. However, the specific role of mucin-type O-glycans in mucus barrier function has been uncertain. Recent studies utilizing mice deficient in key glycosyltransferases involved in O-glycan biosynthesis on intestinal mucins have underscored the importance of mucin-type O-glycosylation in mucus barrier function. This review will highlight recent advances in our understanding of mucin-type O-glycan function in the mucus barrier and how they promote mutualism with our resident microbiota.
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Affiliation(s)
- Kirk S B Bergstrom
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
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847
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Reigstad CS, Kashyap PC. Beyond phylotyping: understanding the impact of gut microbiota on host biology. Neurogastroenterol Motil 2013; 25:358-72. [PMID: 23594242 PMCID: PMC4524550 DOI: 10.1111/nmo.12134] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 03/19/2013] [Indexed: 12/14/2022]
Abstract
BACKGROUND Microbial constituents of the gut microbiome interact with each other and the host to alter the luminal environment and impact development, motility, and homeostasis of the gut. Powerful methods are becoming available to investigate connections between the gut microbiome and human health. While high-throughput sequencing of 16S rRNA genes can be used to identify and enumerate microbes in the gut, advances in several techniques (e.g., metagenomics, metatranscriptomics, metabolomics, and metaproteomics) are providing a clearer view as to the specific activities of the microbiota in the context of functional host-microbe interactions. Testing emergent hypotheses regarding microbial effects on host biology, which arise from analyses of 'Big Data' generated from massive parallel high-throughput sequencing technology and spectroscopic techniques, to guide translational research is an important goal for the future. Insights regarding the fundamental operating principles of the gut microbiota should lay the foundation for rational manipulation of the microbiota to promote human health. PURPOSE In this review, we provide an overview of current research on the gut microbiome emphasizing current state-of-the-art technologies, approaches, and directions for improvement of our understanding of the impact of the gut microbiota with specific focus on gastrointestinal motility disorders.
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Affiliation(s)
- Christopher S. Reigstad
- Department of Gastroenterology and Hepatology; Enteric Neuroscience Program; Mayo Clinic; Rochester; MN; USA
| | - Purna C. Kashyap
- Department of Gastroenterology and Hepatology; Enteric Neuroscience Program; Mayo Clinic; Rochester; MN; USA
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848
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Abstract
Bacteriophages, or simply phages, are viruses infecting bacteria. With an estimated 1031 particles in the biosphere, phages outnumber bacteria by a factor of at least 10 and not surprisingly, they influence the evolution of most bacterial species, sometimes in unexpected ways. “Temperate” phages have the ability to integrate into the chromosome of their host upon infection, where they can reside as “quiescent” prophages until conditions favor their reactivation. Lysogenic conversion resulting from the integration of prophages encoding powerful toxins is probably the most determinant contribution of prophages to the evolution of pathogenic bacteria. We currently grasp only a small fraction of the total phage diversity. Phage biologists keep unraveling novel mechanisms developed by phages to parasitize their host. The purpose of this review is to give an overview of some of the various ways by which prophages change the lifestyle and boost virulence of some of the most dangerous bacterial pathogens.
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Affiliation(s)
- Louis-Charles Fortier
- Département de Microbiologie et d'Infectiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC Canada.
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849
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Bhattacharya A, Eissa NT. Autophagy and autoimmunity crosstalks. Front Immunol 2013; 4:88. [PMID: 23596443 PMCID: PMC3625920 DOI: 10.3389/fimmu.2013.00088] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 04/01/2013] [Indexed: 01/03/2023] Open
Abstract
Autophagy, initially viewed as a conserved bulk-degradation mechanism, has emerged as a central player in a multitude of immune functions. Autophagy is important in host defense against intracellular and extracellular pathogens, metabolic syndromes, immune cell homeostasis, antigen processing and presentation, and maintenance of tolerance. The observation that the above processes are implicated in triggering or exacerbating autoimmunity raises the possibility that autophagy is involved in mediating autoimmune processes, either directly or as a consequence of innate or adaptive functions mediated by the pathway. Genome-wide association studies have shown association between single nucleotide polymorphisms (SNPs) in autophagy related gene 5 (Atg5), and Atg16l1 with susceptibility to systemic lupus erythematosus (SLE) and Crohn’s disease, respectively. Enhanced expression of Atg5 was also reported in blood of mice with experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis (MS), and in T cells isolated from blood or brain tissues from patients with active relapse of MS. This review explores the roles of autophagy pathway in the innate and adaptive immune systems on regulating or mediating the onset, progression, or exacerbation of autoimmune processes.
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850
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O’Hara SP, Tabibian JH, Splinter PL, LaRusso NF. The dynamic biliary epithelia: molecules, pathways, and disease. J Hepatol 2013; 58:575-82. [PMID: 23085249 PMCID: PMC3831345 DOI: 10.1016/j.jhep.2012.10.011] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Revised: 10/01/2012] [Accepted: 10/10/2012] [Indexed: 02/08/2023]
Abstract
Cholangiocytes, the cells lining bile ducts, are a heterogenous, highly dynamic population of epithelial cells. While these cells comprise a small fraction of the total cellular component of the liver, they perform the essential role of bile modification and transport of biliary and blood constituents. From a pathophysiological standpoint, cholangiocytes are the target of a diverse group of biliary disorders, collectively referred to as the cholangiopathies. To date, the cause of most cholangiopathies remains obscure. It is known, however, that cholangiocytes exist in an environment rich in potential mediators of cellular injury, express receptors that recognize potential injurious insults, and participate in portal tract repair processes following hepatic injury. As such, cholangiocytes may not be only a passive target, but are likely directly and actively involved in the pathogenesis of cholangiopathies. Here, we briefly summarize the characteristics of the reactive cholangiocyte and cholangiocyte responses to potentially injurious endogenous and exogenous molecules, and in addition, present emerging concepts in our understanding of the etiopathogenesis of several cholangiopathies.
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Affiliation(s)
- Steven P. O’Hara
- Department of Gastroenterology and Hepatology and the Mayo Clinic Center for Cell Signaling in Gastroenterology, Mayo Clinic, Rochester, MN, United States
| | - James H. Tabibian
- Department of Gastroenterology and Hepatology and the Mayo Clinic Center for Cell Signaling in Gastroenterology, Mayo Clinic, Rochester, MN, United States
| | - Patrick L. Splinter
- Department of Gastroenterology and Hepatology and the Mayo Clinic Center for Cell Signaling in Gastroenterology, Mayo Clinic, Rochester, MN, United States
| | - Nicholas F. LaRusso
- Department of Gastroenterology and Hepatology and the Mayo Clinic Center for Cell Signaling in Gastroenterology, Mayo Clinic, Rochester, MN, United States
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