151
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Intestinal iron homeostasis and colon tumorigenesis. Nutrients 2013; 5:2333-51. [PMID: 23812305 PMCID: PMC3738976 DOI: 10.3390/nu5072333] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 05/29/2013] [Accepted: 06/07/2013] [Indexed: 12/16/2022] Open
Abstract
Colorectal cancer (CRC) is the third most common cause of cancer-related deaths in industrialized countries. Understanding the mechanisms of growth and progression of CRC is essential to improve treatment. Iron is an essential nutrient for cell growth. Iron overload caused by hereditary mutations or excess dietary iron uptake has been identified as a risk factor for CRC. Intestinal iron is tightly controlled by iron transporters that are responsible for iron uptake, distribution, and export. Dysregulation of intestinal iron transporters are observed in CRC and lead to iron accumulation in tumors. Intratumoral iron results in oxidative stress, lipid peroxidation, protein modification and DNA damage with consequent promotion of oncogene activation. In addition, excess iron in intestinal tumors may lead to increase in tumor-elicited inflammation and tumor growth. Limiting intratumoral iron through specifically chelating excess intestinal iron or modulating activities of iron transporter may be an attractive therapeutic target for CRC.
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152
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Stecher B, Berry D, Loy A. Colonization resistance and microbial ecophysiology: using gnotobiotic mouse models and single-cell technology to explore the intestinal jungle. FEMS Microbiol Rev 2013; 37:793-829. [PMID: 23662775 DOI: 10.1111/1574-6976.12024] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 04/11/2013] [Accepted: 04/18/2013] [Indexed: 12/14/2022] Open
Abstract
The highly diverse intestinal microbiota forms a structured community engaged in constant communication with itself and its host and is characterized by extensive ecological interactions. A key benefit that the microbiota affords its host is its ability to protect against infections in a process termed colonization resistance (CR), which remains insufficiently understood. In this review, we connect basic concepts of CR with new insights from recent years and highlight key technological advances in the field of microbial ecology. We present a selection of statistical and bioinformatics tools used to generate hypotheses about synergistic and antagonistic interactions in microbial ecosystems from metagenomic datasets. We emphasize the importance of experimentally testing these hypotheses and discuss the value of gnotobiotic mouse models for investigating specific aspects related to microbiota-host-pathogen interactions in a well-defined experimental system. We further introduce new developments in the area of single-cell analysis using fluorescence in situ hybridization in combination with metabolic stable isotope labeling technologies for studying the in vivo activities of complex community members. These approaches promise to yield novel insights into the mechanisms of CR and intestinal ecophysiology in general, and give researchers the means to experimentally test hypotheses in vivo at varying levels of biological and ecological complexity.
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Affiliation(s)
- Bärbel Stecher
- Max von Pettenkofer Institute of Hygiene and Medical Microbiology, Ludwig-Maximilians-University of Munich, Munich, Germany.
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153
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Abstract
Iron deficiency anemia is the most common form of anemia worldwide, caused by poor iron intake, chronic blood loss, or impaired absorption. Patients with inflammatory bowel disease (IBD) are increasingly likely to have iron deficiency anemia, with an estimated prevalence of 36%–76%. Detection of iron deficiency is problematic as outward signs and symptoms are not always present. Iron deficiency can have a significant impact on a patient’s quality of life, necessitating prompt management and treatment. Effective treatment includes identifying and treating the underlying cause and initiating iron replacement therapy with either oral or intravenous iron. Numerous formulations for oral iron are available, with ferrous fumarate, sulfate, and gluconate being the most commonly prescribed. Available intravenous formulations include iron dextran, iron sucrose, ferric gluconate, and ferumoxytol. Low-molecular weight iron dextran and iron sucrose have been shown to be safe, efficacious, and effective in a host of gastrointestinal disorders. Ferumoxytol is the newest US Food and Drug Administration-approved intravenous iron therapy, indicated for iron deficiency anemia in adults with chronic kidney disease. Ferumoxytol is also being investigated in Phase 3 studies for the treatment of iron deficiency anemia in patients without chronic kidney disease, including subgroups with IBD. A review of the efficacy and safety of iron replacement in IBD, therapeutic considerations, and recommendations for the practicing gastroenterologist are presented.
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Affiliation(s)
- Neil D Goldberg
- Emeritus Chief of Gastroenterology, University of Maryland St. Joseph Medical Center, Towson, MD, USA
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154
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Oral administration of Bifidobacterium longum CECT 7347 ameliorates gliadin-induced alterations in liver iron mobilisation. Br J Nutr 2013; 110:1828-36. [PMID: 23657133 DOI: 10.1017/s0007114513001098] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Coeliac disease is an autoimmune disorder triggered by gluten intake, causing intestinal inflammation and mucosal damage commonly associated with the malabsorption of nutrients and ferropenic anaemia. The present study evaluates the effects of the oral administration of Bifidobacterium longum CECT 7347 on gliadin-mediated alterations in hepatic Fe deposition and Hb concentration, liver transferrin receptor (TfR)-2, IL-6, TNF-α and hepcidin (Hamp) expression (mRNA), and active hepcidin peptide production by liquid chromatography–MS/MS. Weanling rats, sensitised or not with interferon (IFN)-γ, were fed with gliadins and/or the bifidobacterial strain. Gliadin feeding increased hepatic Fe deposition; however, only gliadin-fed sensitised animals showed lower Hb concentrations than the controls. TfR2 expression decreased after gliadins were fed to both sensitised and non-sensitised animals,and restored by the administration of B. longum. These observations were accompanied by increases in IL-6 expression levels in all the treatment groups; however, TNF-α expression only increased significantly in animals fed gliadins alone or together with B. longum if they had previously been sensitised with IFN-γ. Liver expression levels of Hamp diminished in all cases to the lowest values in animals sensitised with IFN-γ after being fed with gliadins and/or bifidobacteria. In these animals, plasma Hamp active peptide concentrations significantly increased when compared with the controls. Significant correlations were calculated between Hamp expression and liver Fe contents (liver Fe = 1/0·0032 + 0·032 x Hamp(exp)), and Hb concentrations (Hb = 11·49 + 10·13 x (Hamp(exp))1/2). These data indicate that oral administration of B. longum ameliorates gliadin-mediated perturbations in liver Fe deposition and mobilisation.
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155
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van Santen S, de Mast Q, Swinkels DW, van der Ven AJAM. The iron link between malaria and invasive non-typhoid Salmonella infections. Trends Parasitol 2013; 29:220-7. [PMID: 23601932 DOI: 10.1016/j.pt.2013.03.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 03/11/2013] [Accepted: 03/12/2013] [Indexed: 02/06/2023]
Abstract
Epidemiological studies have demonstrated an association between malaria and invasive non-typhoid Salmonella (NTS) infections, especially in children. We explore the role of iron as a possible cofactor in this association. Malarial disease, among others, is associated with enhanced erythrophagocytosis and inflammation, which increases the iron content of macrophages and thereby also the survival of Salmonella spp. within macrophages. Whether iron supplementation programs augment the risk of invasive NTS infections in malaria-endemic regions is an important global health issue that still needs to be determined.
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Affiliation(s)
- Susanne van Santen
- Department of General Internal Medicine, Nijmegen Institute for International Health (456), Radboud University Medical Center, Geert Grooteplein Zuid 8, PO Box 9101, 6500 HB Nijmegen, The Netherlands
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156
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The intestinal microbiota in the rat model: major breakthroughs from new technologies. Anim Health Res Rev 2013; 13:54-63. [PMID: 22853927 DOI: 10.1017/s1466252312000072] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The mammalian intestine harbors a large and diverse community of micro-organisms, known as the intestinal microbiota. Recent developments in molecular profiling methods, mainly based on microbial 16S ribosomal RNA gene sequencing, have provided unprecedented insights into the make-up and diversity of intestinal microbial communities. Using these culture-independent analyses, gut microbiota of several mammals including laboratory rodents, have been revisited. The laboratory rat is one of the major species bred and kept for scientific research. Although this animal is bred in confined environments and subjected to procedures for satisfying health requirements that hamper natural colonization, some major features of mammalian gut microbiota are conserved. However, the gut microbiota varies according to the breeding conditions of the rats and this could impact reproducibility of the experimental models. Determining the non-pathogenic microbial community might be relevant in standards of quality control of laboratory animals. Molecular profiling techniques could be applied to document this information.
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157
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Ryan EP, Heuberger AL, Broeckling CD, Borresen EC, Tillotson C, Prenni JE. Advances in Nutritional Metabolomics. ACTA ACUST UNITED AC 2013; 1:109-120. [PMID: 29682447 DOI: 10.2174/2213235x11301020001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Metabolomics is maturing as an experimental approach in nutrition science, and it is a useful analysis for revealing systems biology outcomes associated with changes in diet. A major goal of this review is to present the rapidly evolving body of scientific literature that seeks to reveal connections between an individual's metabolic profile and experimentally manipulated or naturally varied dietary intakes. Metabolite profiles in tissue, serum, urine, or stool reflect changes in metabolic pathways that respond to dietary intervention which makes them accessible samples for revealing metabolic effects of diet. Three broadly defined areas of investigation related to dietary-metabolomic strategies include: (1) describing the metabolite variation within and between dietary exposures or interventions; (2) characterizing the metabolic response to dietary interventions with respect to time; and (3) assessing individual variation in baseline nutritional health and/or disease status. An overview of metabolites that were responsive to dietary interventions as reported from original research in human or animal studies is provided and illustrates the breadth of metabolites affected by dietary intervention. Advantages and drawbacks for assessing metabolic changes are discussed in relation to types of metabolite analysis platforms. A combination of targeted and non-targeted global profiling studies as a component of future dietary intervention trials will increase our understanding of nutrition in a systems context.
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Affiliation(s)
- Elizabeth P Ryan
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins CO 80523
| | - Adam L Heuberger
- Proteomics and Metabolomics Facility, Colorado State University, Fort Collins CO 80523
| | - Corey D Broeckling
- Proteomics and Metabolomics Facility, Colorado State University, Fort Collins CO 80523
| | - Erica C Borresen
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins CO 80523
| | - Cadie Tillotson
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins CO 80523
| | - Jessica E Prenni
- Proteomics and Metabolomics Facility, Colorado State University, Fort Collins CO 80523.,Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins CO 80523
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158
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Dostal A, Fehlbaum S, Chassard C, Zimmermann MB, Lacroix C. Low iron availability in continuous in vitro colonic fermentations induces strong dysbiosis of the child gut microbial consortium and a decrease in main metabolites. FEMS Microbiol Ecol 2013; 83:161-75. [PMID: 22845175 PMCID: PMC3511601 DOI: 10.1111/j.1574-6941.2012.01461.x] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Revised: 07/13/2012] [Accepted: 07/19/2012] [Indexed: 12/31/2022] Open
Abstract
Iron (Fe) deficiency affects an estimated 2 billion people worldwide, and Fe supplements are a common corrective strategy. The impact of Fe deficiency and Fe supplementation on the complex microbial community of the child gut was studied using in vitro colonic fermentation models inoculated with immobilized fecal microbiota. Chyme media (all Fe chelated by 2,2'-dipyridyl to 26.5 mg Fe L(-1) ) mimicking Fe deficiency and supplementation were continuously fermented. Fermentation effluent samples were analyzed daily on the microbial composition and metabolites by quantitative PCR, 16S rRNA gene 454-pyrosequencing, and HPLC. Low Fe conditions (1.56 mg Fe L(-1) ) significantly decreased acetate concentrations, and subsequent Fe supplementation (26.5 mg Fe L(-1) ) restored acetate production. High Fe following normal Fe conditions had no impact on the gut microbiota composition and metabolic activity. During very low Fe conditions (0.9 mg Fe L(-1) or Fe chelated by 2,2'-dipyridyl), a decrease in Roseburia spp./Eubacterium rectale, Clostridium Cluster IV members and Bacteroides spp. was observed, while Lactobacillus spp. and Enterobacteriaceae increased consistent with a decrease in butyrate (-84%) and propionate (-55%). The strong dysbiosis of the gut microbiota together with decrease in main gut microbiota metabolites observed with very low iron conditions could weaken the barrier effect of the microbiota and negatively impact gut health.
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Affiliation(s)
- Alexandra Dostal
- Laboratory of Food Biotechnology, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
| | - Sophie Fehlbaum
- Laboratory of Food Biotechnology, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
| | - Christophe Chassard
- Laboratory of Food Biotechnology, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
| | - Michael Bruce Zimmermann
- Laboratory of Human Nutrition, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
| | - Christophe Lacroix
- Laboratory of Food Biotechnology, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
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159
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Holmes E, Li JV, Marchesi JR, Nicholson JK. Gut microbiota composition and activity in relation to host metabolic phenotype and disease risk. Cell Metab 2012; 16:559-64. [PMID: 23140640 DOI: 10.1016/j.cmet.2012.10.007] [Citation(s) in RCA: 345] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 09/17/2012] [Accepted: 10/22/2012] [Indexed: 12/16/2022]
Abstract
The symbiotic gut microbiota modulate health and disease of the host through a series of transgenomic metabolic and immune regulatory axes. We explore connections between microbiome composition and function related to individual metabolic phenotypes and consider these interactions as possible targets for developing new personalized therapies and clinical management strategies.
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Affiliation(s)
- Elaine Holmes
- Biomolecular Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Sir Alexander Fleming Building, South Kensington, London SW7 2AZ, UK
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160
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Inhibition of Fe-induced colon oxidative stress by lactobacilli in mice. World J Microbiol Biotechnol 2012; 29:209-16. [DOI: 10.1007/s11274-012-1172-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 09/14/2012] [Indexed: 01/27/2023]
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161
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Bengmark S. Gut microbiota, immune development and function. Pharmacol Res 2012; 69:87-113. [PMID: 22989504 DOI: 10.1016/j.phrs.2012.09.002] [Citation(s) in RCA: 142] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 09/01/2012] [Indexed: 02/08/2023]
Abstract
The microbiota of Westerners is significantly reduced in comparison to rural individuals living a similar lifestyle to our Paleolithic forefathers but also to that of other free-living primates such as the chimpanzee. The great majority of ingredients in the industrially produced foods consumed in the West are absorbed in the upper part of small intestine and thus of limited benefit to the microbiota. Lack of proper nutrition for microbiota is a major factor under-pinning dysfunctional microbiota, dysbiosis, chronically elevated inflammation, and the production and leakage of endotoxins through the various tissue barriers. Furthermore, the over-comsumption of insulinogenic foods and proteotoxins, such as advanced glycation and lipoxidation molecules, gluten and zein, and a reduced intake of fruit and vegetables, are key factors behind the commonly observed elevated inflammation and the endemic of obesity and chronic diseases, factors which are also likely to be detrimental to microbiota. As a consequence of this lifestyle and the associated eating habits, most barriers, including the gut, the airways, the skin, the oral cavity, the vagina, the placenta, the blood-brain barrier, etc., are increasingly permeable. Attempts to recondition these barriers through the use of so called 'probiotics', normally applied to the gut, are rarely successful, and sometimes fail, as they are usually applied as adjunctive treatments, e.g. in parallel with heavy pharmaceutical treatment, not rarely consisting in antibiotics and chemotherapy. It is increasingly observed that the majority of pharmaceutical drugs, even those believed to have minimal adverse effects, such as proton pump inhibitors and anti-hypertensives, in fact adversely affect immune development and functions and are most likely also deleterious to microbiota. Equally, it appears that probiotic treatment is not compatible with pharmacological treatments. Eco-biological treatments, with plant-derived substances, or phytochemicals, e.g. curcumin and resveratrol, and pre-, pro- and syn-biotics offers similar effects as use of biologicals, although milder but also free from adverse effects. Such treatments should be tried as alternative therapies; mainly, to begin with, for disease prevention but also in early cases of chronic diseases. Pharmaceutical treatment has, thus far, failed to inhibit the tsunami of endemic diseases spreading around the world, and no new tools are in sight. Dramatic alterations, in direction of a paleolithic-like lifestyle and food habits, seem to be the only alternatives with the potential to control the present escalating crisis. The present review focuses on human studies, especially those of clinical relevance.
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Affiliation(s)
- Stig Bengmark
- Division of Surgery & Interventional Science, University College London, 4th floor, 74 Huntley Street, London WC1E 6AU, United Kingdom.
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162
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Genetic modification of iron metabolism in mice affects the gut microbiota. Biometals 2012; 25:883-92. [DOI: 10.1007/s10534-012-9555-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Accepted: 04/27/2012] [Indexed: 12/19/2022]
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