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Gut Microbiota-Derived Mediators as Potential Markers in Nonalcoholic Fatty Liver Disease. BIOMED RESEARCH INTERNATIONAL 2019; 2019:8507583. [PMID: 30719448 PMCID: PMC6334327 DOI: 10.1155/2019/8507583] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 12/20/2018] [Indexed: 12/17/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a common, multifactorial, and poorly understood liver disease whose incidence is globally rising. During the past decade, several lines of evidence suggest that dysbiosis of intestinal microbiome represents an important factor contributing to NAFLD occurrence and its progression into NASH. The mechanisms that associate dysbiosis with NAFLD include changes in microbiota-derived mediators, deregulation of the gut endothelial barrier, translocation of mediators of dysbiosis, and hepatic inflammation. Changes in short chain fatty acids, bile acids, bacterial components, choline, and ethanol are the result of altered intestinal microbiota. We perform a narrative review of the previously published evidence and discuss the use of gut microbiota-derived mediators as potential markers in NAFLD.
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152
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Antimicrobial proteins: intestinal guards to protect against liver disease. J Gastroenterol 2019; 54:209-217. [PMID: 30392013 PMCID: PMC6391196 DOI: 10.1007/s00535-018-1521-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 10/19/2018] [Indexed: 02/07/2023]
Abstract
Alterations of gut microbes play a role in the pathogenesis and progression of many disorders including liver and gastrointestinal diseases. Both qualitative and quantitative changes in gut microbiota have been associated with liver disease. Intestinal dysbiosis can disrupt the integrity of the intestinal barrier leading to pathological bacterial translocation and the initiation of an inflammatory response in the liver. In order to sustain symbiosis and protect from pathological bacterial translocation, antimicrobial proteins (AMPs) such as a-defensins and C-type lectins are expressed in the gastrointestinal tract. In this review, we provide an overview of the role of AMPs in different chronic liver disease such as alcoholic steatohepatitis, non-alcoholic fatty liver disease, and cirrhosis. In addition, potential approaches to modulate the function of AMPs and prevent bacterial translocation are discussed.
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153
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Grabherr F, Grander C, Effenberger M, Adolph TE, Tilg H. Gut Dysfunction and Non-alcoholic Fatty Liver Disease. Front Endocrinol (Lausanne) 2019; 10:611. [PMID: 31555219 PMCID: PMC6742694 DOI: 10.3389/fendo.2019.00611] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 08/22/2019] [Indexed: 12/12/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) has emerged as one of the leading liver diseases worldwide. NAFLD is characterized by hepatic steatosis and may progress to an inflammatory condition termed non-alcoholic steatohepatitis (NASH), liver cirrhosis, and hepatocellular carcinoma. It became evident in the last years that NAFLD pathophysiology is complex and involves diverse immunological and metabolic pathways. An association between intestinal signals (e.g., derived from the gut microbiota) and the development of obesity and its metabolic consequences such as NAFLD are increasingly recognized. Pre-clinical studies have shown that germ-free mice are protected against obesity and hepatic steatosis. Several human studies from the past years have demonstrated that NAFLD contains a disease-specific gut microbiome signature. Controlled studies propose that certain bacteria with rather pro-inflammatory features such as Proteobacteria or Escherichia coli are dominantly present in these patients. In contrast, rather protective bacteria such as Faecalibacterium prausnitzii are decreased in NAFLD patients. Furthermore, various bacterial metabolites and microbiota-generated secondary bile acids are involved in NAFLD-associated metabolic dysfunction. Although these findings are exciting, research currently lack evidence that interference at the level of the gut microbiome is beneficial for these diseases. Further preclinical and clinical studies are needed to advance this aspect of NAFLD research and to support the notion that the intestinal microbiota is indeed of major relevance in this disorder.
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154
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Chen K, Ma J, Jia X, Ai W, Ma Z, Pan Q. Advancing the understanding of NAFLD to hepatocellular carcinoma development: From experimental models to humans. Biochim Biophys Acta Rev Cancer 2018; 1871:117-125. [PMID: 30528647 DOI: 10.1016/j.bbcan.2018.11.005] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 10/28/2018] [Accepted: 11/23/2018] [Indexed: 02/06/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) has recently been recognized as an important etiology contributing to the increased incidence of hepatocellular carcinoma (HCC). NAFLD, characterized by fat accumulation in the liver, is affecting at least one-third of the global population. The more aggressive form, nonalcoholic steatohepatitis (NASH), is characterized by hepatocyte necrosis and inflammation. The development of effective approaches for disease prevention and/or treatment heavily relies on deep understanding of the mechanisms underlying NAFLD to HCC development. However, this has been largely hampered by the lack of robust experimental models that recapitulate the full disease spectrum. This review will comprehensively describe the current in vitro and mouse models for studying NAFLD/NASH/HCC, and further emphasize their applications and possible future improvement for better understanding the molecular mechanisms involved in the cascade of NAFLD to HCC progression.
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Affiliation(s)
- Kan Chen
- College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China; Biomedical Research Center, Northwest Minzu University, Lanzhou, China; Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
| | - Jianbo Ma
- Biomedical Research Center, Northwest Minzu University, Lanzhou, China; Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
| | - Xiaoyuan Jia
- College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - Wen Ai
- Department of Cardiology, Shenzhen Nanshan People's Hospital, China
| | - Zhongren Ma
- Biomedical Research Center, Northwest Minzu University, Lanzhou, China
| | - Qiuwei Pan
- College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China; Biomedical Research Center, Northwest Minzu University, Lanzhou, China; Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands.
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155
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Tripathi A, Debelius J, Brenner DA, Karin M, Loomba R, Schnabl B, Knight R. Publisher Correction: The gut-liver axis and the intersection with the microbiome. Nat Rev Gastroenterol Hepatol 2018; 15:785. [PMID: 29785003 PMCID: PMC7133393 DOI: 10.1038/s41575-018-0031-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In the original version of Table 1 published online, upward arrows to indicate increased translocation of PAMPs were missing from the row entitled 'Translocation' for both the column on alcoholic liver disease and nonalcoholic fatty liver disease. This error has now been updated in the PDF and HTML version of the article.
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156
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Colon Epithelial MicroRNA Network in Fatty Liver. Can J Gastroenterol Hepatol 2018; 2018:8246103. [PMID: 30345259 PMCID: PMC6174781 DOI: 10.1155/2018/8246103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 08/15/2018] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND & AIMS Intestinal barrier alterations are associated with fatty liver (FL) and metabolic syndrome (MetS), but microRNA (miR) signaling pathways in MetS-FL pathogenesis remain unclear. This study investigates an epithelial-focused miR network in colorectal cell models based on the previously reported MetS-FL miR trio of hsa-miR-142-3p, hsa-miR-18b, and hsa-miR-890. METHODS Each miR mimic construct of MetS-FL miR trio was transfected into human colorectal cells, CRL-1790 or Caco-2. Global miRNome changes posttransfection were profiled (nCounter® Human v3 miRNA, NanoString Technologies). Changes in barrier (transepithelial electrical resistance, TEER) and epithelial cell junction structure (Occludin and Zona Occludens-1/ZO-1 immunofluorescence staining-confocal microscopy) were examined pre- and posttransfection in Caco-2 cell monolayers. A signaling network was constructed from the MetS-FL miR trio, MetS-FL miR-induced colorectal miRNome changes, ZO-1, and Occludin. RESULTS Transfection of CRL-1790 cells with each MetS-FL miR mimic led to global changes in the cellular miRNome profile, with 288 miRs being altered in expression by more than twofold. Eleven miRs with known cytoskeletal and metabolic roles were commonly altered in expression by all three miR mimics. Transfection of Caco-2 cell monolayers with each MetS-FL miR mimic induced barrier-associated TEER variations and led to structural modifications of ZO-1 and Occludin within epithelial cell junctions. Pathway analysis incorporating the MetS-FL miR trio, eleven common target miRs, ZO-1, and Occludin revealed a signaling network centered on TNF and AKT2, which highlights injury, inflammation, and hyperplasia. CONCLUSIONS Colon-specific changes in epithelial barriers, cell junction structure, and a miRNome signaling network are described from functional studies of a MetS-FL miR trio signature.
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157
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Xia F, Zhou BJ. Role of gut-liver axis dysfunction in pathogenesis of non-alcoholic fatty liver disease: Implications for treatment strategies. Shijie Huaren Xiaohua Zazhi 2018; 26:1439-1447. [DOI: 10.11569/wcjd.v26.i24.1439] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is a chronic metabolic disease whose pathogenesis is not fully understood and involves multiple factors. Metabolic disorder caused by gut microbial imbalance is a key factor contributing to the development of NAFLD. Several studies show that gut barrier dysfunction will cause the occurrence of toxic metabolites in blood and bacterial translocation. The "dialogue" between the gut and the liver highlights the key role of the gut-liver axis in the process of NAFLD. This paper will summarize the relationship between the gut-liver axis and the pathogenesis of NAFLD, as well as its implications for the treatment of NAFLD.
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Affiliation(s)
- Fan Xia
- Department of Pharmacy, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen 518017, Guangdong Province, China
| | - Ben-Jie Zhou
- Department of Pharmacy, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen 518017, Guangdong Province, China
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158
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Tripathi A, Debelius J, Brenner DA, Karin M, Loomba R, Schnabl B, Knight R. The gut-liver axis and the intersection with the microbiome. Nat Rev Gastroenterol Hepatol 2018; 15:397-411. [PMID: 29748586 PMCID: PMC6319369 DOI: 10.1038/s41575-018-0011-z] [Citation(s) in RCA: 797] [Impact Index Per Article: 132.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In the past decade, an exciting realization has been that diverse liver diseases - ranging from nonalcoholic steatohepatitis, alcoholic steatohepatitis and cirrhosis to hepatocellular carcinoma - fall along a spectrum. Work on the biology of the gut-liver axis has assisted in understanding the basic biology of both alcoholic fatty liver disease and nonalcoholic fatty liver disease (NAFLD). Of immense importance is the advancement in understanding the role of the microbiome, driven by high-throughput DNA sequencing and improved computational techniques that enable the complexity of the microbiome to be interrogated, together with improved experimental designs. Here, we review gut-liver communications in liver disease, exploring the molecular, genetic and microbiome relationships and discussing prospects for exploiting the microbiome to determine liver disease stage and to predict the effects of pharmaceutical, dietary and other interventions at a population and individual level. Although much work remains to be done in understanding the relationship between the microbiome and liver disease, rapid progress towards clinical applications is being made, especially in study designs that complement human intervention studies with mechanistic work in mice that have been humanized in multiple respects, including the genetic, immunological and microbiome characteristics of individual patients. These 'avatar mice' could be especially useful for guiding new microbiome-based or microbiome-informed therapies.
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Affiliation(s)
- Anupriya Tripathi
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
- Department of Pediatrics, University of California, San Diego, CA, USA
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, CA, USA
| | - Justine Debelius
- Department of Pediatrics, University of California, San Diego, CA, USA
| | - David A Brenner
- NAFLD Research Center, Division of Gastroenterology, Department of Medicine, University of California, San Diego, CA, USA
| | - Michael Karin
- Department of Pediatrics, University of California, San Diego, CA, USA
- Department of Computer Science and Engineering, University of California, San Diego, CA, USA
| | - Rohit Loomba
- NAFLD Research Center, Division of Gastroenterology, Department of Medicine, University of California, San Diego, CA, USA
- Center for Microbiome Innovation, University of California, San Diego, CA, USA
| | - Bernd Schnabl
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
- Department of Medicine, VA San Diego Healthcare System, San Diego, CA, USA
- Center for Microbiome Innovation, University of California, San Diego, CA, USA
| | - Rob Knight
- Department of Pediatrics, University of California, San Diego, CA, USA.
- Department of Computer Science and Engineering, University of California, San Diego, CA, USA.
- Center for Microbiome Innovation, University of California, San Diego, CA, USA.
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159
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Luther J, Gala MK, Borren N, Masia R, Goodman RP, Moeller IH, DiGiacomo E, Ehrlich A, Warren A, Yarmush ML, Ananthakrishnan A, Corey K, Kaplan LM, Bhatia S, Chung RT, Patel SJ. Hepatic connexin 32 associates with nonalcoholic fatty liver disease severity. Hepatol Commun 2018; 2:786-797. [PMID: 30202815 PMCID: PMC6123534 DOI: 10.1002/hep4.1179] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 02/01/2018] [Accepted: 02/02/2018] [Indexed: 12/17/2022] Open
Abstract
Emerging data highlight the critical role for the innate immune system in the progression of nonalcoholic fatty liver disease (NAFLD). Connexin 32 (Cx32), the primary liver gap junction protein, is capable of modulating hepatic innate immune responses and has been studied in dietary animal models of steatohepatitis. In this work, we sought to determine the association of hepatic Cx32 with the stages of human NAFLD in a histologically characterized cohort of 362 patients with NAFLD. We also studied the hepatic expression of the genes and proteins known to interact with Cx32 (known as the connexome) in patients with NAFLD. Last, we used three independent dietary mouse models of nonalcoholic steatohepatitis to investigate the role of Cx32 in the development of steatohepatitis and fibrosis. In a univariate analysis, we found that Cx32 hepatic expression associates with each component of the NAFLD activity score and fibrosis severity. Multivariate analysis revealed that Cx32 expression most closely associated with the NAFLD activity score and fibrosis compared to known risk factors for the disease. Furthermore, by analyzing the connexome, we identified novel genes related to Cx32 that associate with NAFLD progression. Finally, we demonstrated that Cx32 deficiency protects against liver injury, inflammation, and fibrosis in three murine models of nonalcoholic steatohepatitis by limiting initial diet-induced hepatoxicity and subsequent increases in intestinal permeability. Conclusion: Hepatic expression of Cx32 strongly associates with steatohepatitis and fibrosis in patients with NAFLD. We also identify novel genes associated with NAFLD and suggest that Cx32 plays a role in promoting NAFLD development. (Hepatology Communications 2018;2:786-797).
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Affiliation(s)
- Jay Luther
- Gastrointestinal Unit, Department of MedicineMassachusetts General Hospital, Harvard Medical SchoolBostonMA
- Clinical and Translational Unit, Department of MedicineMassachusetts General Hospital, Harvard Medical SchoolBostonMA
- Obesity, Metabolism, and Nutrition InstituteMassachusetts General Hospital, Harvard Medical SchoolBostonMA
| | - Manish K. Gala
- Gastrointestinal Unit, Department of MedicineMassachusetts General Hospital, Harvard Medical SchoolBostonMA
- Clinical and Translational Unit, Department of MedicineMassachusetts General Hospital, Harvard Medical SchoolBostonMA
| | - Nynke Borren
- Gastrointestinal Unit, Department of MedicineMassachusetts General Hospital, Harvard Medical SchoolBostonMA
| | - Ricard Masia
- Pathology Unit, Massachusetts General HospitalHarvard Medical SchoolBostonMA
| | - Russell P. Goodman
- Gastrointestinal Unit, Department of MedicineMassachusetts General Hospital, Harvard Medical SchoolBostonMA
| | - Ida Hatoum Moeller
- Gastrointestinal Unit, Department of MedicineMassachusetts General Hospital, Harvard Medical SchoolBostonMA
- Obesity, Metabolism, and Nutrition InstituteMassachusetts General Hospital, Harvard Medical SchoolBostonMA
| | - Erik DiGiacomo
- Gastrointestinal Unit, Department of MedicineMassachusetts General Hospital, Harvard Medical SchoolBostonMA
| | - Alyssa Ehrlich
- Gastrointestinal Unit, Department of MedicineMassachusetts General Hospital, Harvard Medical SchoolBostonMA
| | | | - Martin L. Yarmush
- Center for Engineering in Medicine, Shriner's HospitalHarvard Medical SchoolBostonMA
| | - Ashwin Ananthakrishnan
- Gastrointestinal Unit, Department of MedicineMassachusetts General Hospital, Harvard Medical SchoolBostonMA
| | - Kathleen Corey
- Gastrointestinal Unit, Department of MedicineMassachusetts General Hospital, Harvard Medical SchoolBostonMA
| | - Lee M. Kaplan
- Gastrointestinal Unit, Department of MedicineMassachusetts General Hospital, Harvard Medical SchoolBostonMA
- Obesity, Metabolism, and Nutrition InstituteMassachusetts General Hospital, Harvard Medical SchoolBostonMA
| | | | - Raymond T. Chung
- Gastrointestinal Unit, Department of MedicineMassachusetts General Hospital, Harvard Medical SchoolBostonMA
| | - Suraj J. Patel
- Gastrointestinal Unit, Department of MedicineMassachusetts General Hospital, Harvard Medical SchoolBostonMA
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160
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Strey CBM, de Carli LA, Fantinelli M, Gobbato SS, Bassols GF, Losekann A, Coral GP. Impact of Diabetes Mellitus and Insulin on Nonalcoholic Fatty Liver Disease in the Morbidly Obese. Ann Hepatol 2018; 17:585-591. [PMID: 29893699 DOI: 10.5604/01.3001.0012.0922] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
INTRODUCTION AND AIM The prevalence of obesity, type 2 diabetes mellitus and non-alcoholic fatty liver disease are increasing. Type 2 diabetes mellitus may aggravate non-alcoholic fatty liver disease, increasing the risk of developing cirrhosis and hepatocellular carcinoma. This study aims to determine the effect of type 2 diabetes mellitus and insulin therapy on non-alcoholic fatty liver disease in the patients with morbid obesity. MATERIAL AND METHODS Clinical, anthropometric and laboratory data were analyzed together with intraoperative liver biopsies from morbidly obese patients undergoing bariatric surgery. RESULTS 219 patients with morbid obesity were evaluated. Systemic arterial hypertension (55.9% vs. 33.8%, p = 0.004) and dyslipidemia (67.1% vs. 39.0%, p < 0.001) were more prevalent in patients with diabetes when compared to patients without diabetes. In multivariate analysis, type 2 diabetes mellitus was an independent risk factor for severe steatosis (RR = 2.04, p = 0.023) and severe fibrosis (RR = 4.57, p = 0.013). Insulin therapy was significantly associated with non-alcoholic steatohepatitis (RR = 1.89, p = 0.001) and fibrosis (RR = 1.75, p = 0.050) when all patients were analysed, but when only patients with diabetes were analysed, insulin therapy was not associated with non-alcoholic steatohepatitis or fibrosis. CONCLUSION Type 2 diabetes mellitus plays an important role in the progression of non-alcoholic fatty liver disease as an independent risk factor for severe fibrosis.
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Affiliation(s)
- Cláudia B M Strey
- Department of Hepatology, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, Brazil
| | - Luiz A de Carli
- Obesity Treatment Center, Santa Casa de Misericórdia de Porto Alegre, Porto Alegre, RS, Brazil
| | - Marciane Fantinelli
- Obesity Treatment Center, Santa Casa de Misericórdia de Porto Alegre, Porto Alegre, RS, Brazil
| | - Sabrina S Gobbato
- Obesity Treatment Center, Santa Casa de Misericórdia de Porto Alegre, Porto Alegre, RS, Brazil
| | - Guilherme F Bassols
- Obesity Treatment Center, Santa Casa de Misericórdia de Porto Alegre, Porto Alegre, RS, Brazil
| | - Alexandre Losekann
- Department of Internal Medicine, Faculdade de Medicina da Pontifícia Universidade Católica do Rio Grande do Sul, Proto Alegre, RS, Brazil
| | - Gabriela P Coral
- Department of Hepatology, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, Brazil
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161
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Shen TCD, Pyrsopoulos N, Rustgi VK. Microbiota and the liver. Liver Transpl 2018; 24:539-550. [PMID: 29316191 DOI: 10.1002/lt.25008] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 12/01/2017] [Accepted: 12/19/2017] [Indexed: 02/07/2023]
Abstract
The gut microbiome outnumbers the human genome by 150-fold and plays important roles in metabolism, immune system education, tolerance development, and prevention of pathogen colonization. Dysbiosis has been associated with nonalcoholic fatty liver disease (NAFLD), nonalcoholic steatohepatitis (NASH), and alcoholic liver disease (ALD) as well as cirrhosis and complications. This article provides an overview of this relationship. Liver Transplantation 24 539-550 2018 AASLD.
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Affiliation(s)
- Ting-Chin David Shen
- Division of Gastroenterology and Hepatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Nikolaos Pyrsopoulos
- Department of Gastroenterology and Hepatology, Rutgers New Jersey Medical School, Newark, NJ
| | - Vinod K Rustgi
- Division of Gastroenterology and Hepatology, Robert Wood Johnson School of Medicine, Rutgers Health, New Brunswick, NJ
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162
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Origins of Portal Hypertension in Nonalcoholic Fatty Liver Disease. Dig Dis Sci 2018; 63:563-576. [PMID: 29368124 DOI: 10.1007/s10620-017-4903-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 12/26/2017] [Indexed: 02/06/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) advanced to cirrhosis is often complicated by clinically significant portal hypertension, which is primarily caused by increased intrahepatic vascular resistance. Liver fibrosis has been identified as a critical determinant of this process. However, there is evidence that portal venous pressure may begin to rise in the earliest stages of NAFLD when fibrosis is far less advanced or absent. The biological and clinical significance of these early changes in sinusoidal homeostasis remains unclear. Experimental and human observations indicate that sinusoidal space restriction due to hepatocellular lipid accumulation and ballooning may impair sinusoidal flow and generate shear stress, increasingly disrupting sinusoidal microcirculation. Sinusoidal endothelial cells, hepatic stellate cells, and Kupffer cells are key partners of hepatocytes affected by NAFLD in promoting endothelial dysfunction through enhanced contractility, capillarization, adhesion and entrapment of blood cells, extracellular matrix deposition, and neovascularization. These biomechanical and rheological changes are aggravated by a dysfunctional gut-liver axis and splanchnic vasoregulation, culminating in fibrosis and clinically significant portal hypertension. We may speculate that increased portal venous pressure is an essential element of the pathogenesis across the entire spectrum of NAFLD. Improved methods of noninvasive portal venous pressure monitoring will hopefully give new insights into the pathobiology of NAFLD and help efforts to identify patients at increased risk for adverse outcomes. In addition, novel drug candidates targeting reversible components of aberrant sinusoidal circulation may prevent progression in NAFLD.
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163
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Simpson SJ, Raubenheimer D, Cogger VC, Macia L, Solon-Biet SM, Le Couteur DG, George J. The nutritional geometry of liver disease including non-alcoholic fatty liver disease. J Hepatol 2018; 68:316-325. [PMID: 29122389 DOI: 10.1016/j.jhep.2017.10.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 10/06/2017] [Accepted: 10/10/2017] [Indexed: 12/23/2022]
Abstract
Nutrition has a profound effect on chronic liver disease, especially non-alcoholic fatty liver disease (NAFLD). Most observational studies and clinical trials have focussed on the effects of total energy intake, or the intake of individual macronutrients and certain micronutrients, such as vitamin D, on liver disease. Although these studies have shown the importance of nutrition on hepatic outcomes, there is not yet any unifying framework for understanding the relationship between diet and liver disease. The Geometric Framework for Nutrition (GFN) is an innovative model for designing nutritional experiments or interpreting nutritional data that can determine the effects of nutrients and their interactions on animal behaviour and phenotypes. Recently the GFN has provided insights into the relationship between dietary energy and macronutrients on obesity and ageing in mammals including humans. Mouse studies using the GFN have disentangled the effects of macronutrients on fatty liver and the gut microbiome. The GFN is likely to play a significant role in disentangling the effects of nutrients on liver disease, especially NAFLD, in humans.
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Affiliation(s)
- Stephen J Simpson
- The University of Sydney, Charles Perkins Centre, Sydney, NSW, Australia.
| | - David Raubenheimer
- The University of Sydney, Charles Perkins Centre, Sydney, NSW, Australia; The University of Sydney, School of Life and Environmental Sciences, Sydney, NSW, Australia
| | - Victoria C Cogger
- The University of Sydney, Charles Perkins Centre, Sydney, NSW, Australia; Centre for Education and Research on Ageing and the ANZAC Research Institute, Concord Hospital and The University of Sydney, Sydney, NSW, Australia
| | - Laurence Macia
- The University of Sydney, Charles Perkins Centre, Sydney, NSW, Australia; The University of Sydney, School of Medical Sciences, Sydney Medical School, Sydney, NSW, Australia
| | - Samantha M Solon-Biet
- The University of Sydney, Charles Perkins Centre, Sydney, NSW, Australia; The University of Sydney, School of Life and Environmental Sciences, Sydney, NSW, Australia
| | - David G Le Couteur
- The University of Sydney, Charles Perkins Centre, Sydney, NSW, Australia; Centre for Education and Research on Ageing and the ANZAC Research Institute, Concord Hospital and The University of Sydney, Sydney, NSW, Australia
| | - Jacob George
- Storr Liver Centre, Westmead Institute for Medical Research, Westmead Hospital and The University of Sydney, Sydney, NSW, Australia.
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164
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Wang W, Zhao J, Gui W, Sun D, Dai H, Xiao L, Chu H, Du F, Zhu Q, Schnabl B, Huang K, Yang L, Hou X. Tauroursodeoxycholic acid inhibits intestinal inflammation and barrier disruption in mice with non-alcoholic fatty liver disease. Br J Pharmacol 2018; 175:469-484. [PMID: 29139555 DOI: 10.1111/bph.14095] [Citation(s) in RCA: 106] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2017] [Revised: 10/08/2017] [Accepted: 10/31/2017] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND AND PURPOSE The gut-liver axis is associated with the progression of non-alcoholic fatty liver disease (NAFLD). Targeting the gut-liver axis and bile acid-based pharmaceuticals are potential therapies for NAFLD. The effect of tauroursodeoxycholic acid (TUDCA), a candidate drug for NAFLD, on intestinal barrier function, intestinal inflammation, gut lipid transport and microbiota composition was analysed in a murine model of NAFLD. EXPERIMENTAL APPROACH The NAFLD mouse model was established by feeding mice a high-fat diet (HFD) for 16 weeks. TUDCA was administered p.o. during the last 4 weeks. The expression levels of intestinal tight junction genes, lipid metabolic and inflammatory genes were determined by quantitative PCR. Tissue inflammation was evaluated by haematoxylin and eosin staining. The gut microbiota was analysed by 16S rRNA gene sequencing. KEY RESULTS TUDCA administration attenuated HFD-induced hepatic steatosis, inflammatory responses, obesity and insulin resistance in mice. Moreover, TUDCA attenuated gut inflammatory responses as manifested by decreased intestinal histopathology scores and inflammatory cytokine levels. In addition, TUDCA improved intestinal barrier function by increasing levels of tight junction molecules and the solid chemical barrier. The components involved in ileum lipid transport were also reduced by TUDCA administration in HFD-fed mice. Finally, the TUDCA-treated mice showed a different gut microbiota composition compared with that in HFD-fed mice but similar to that in normal chow diet-fed mice. CONCLUSIONS AND IMPLICATIONS TUDCA attenuates the progression of HFD-induced NAFLD in mice by ameliorating gut inflammation, improving intestinal barrier function, decreasing intestinal fat transport and modulating intestinal microbiota composition.
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Affiliation(s)
- Weijun Wang
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jinfang Zhao
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Wenfang Gui
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Dan Sun
- Division of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Haijiang Dai
- Center of Clinical Pharmacology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Li Xiao
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Huikuan Chu
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Fan Du
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | | | - Bernd Schnabl
- Department of Medicine, Biomedical Research Facility 2 (BRF2), University of California, San Diego, La Jolla, CA, USA
| | - Kai Huang
- Division of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ling Yang
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaohua Hou
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Takahashi H, Kotani K, Tanaka K, Egucih Y, Anzai K. Therapeutic Approaches to Nonalcoholic Fatty Liver Disease: Exercise Intervention and Related Mechanisms. Front Endocrinol (Lausanne) 2018; 9:588. [PMID: 30374329 PMCID: PMC6196235 DOI: 10.3389/fendo.2018.00588] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 09/17/2018] [Indexed: 12/16/2022] Open
Abstract
Exercise training ameliorates nonalcoholic fatty liver disease (NAFLD) as well as obesity and metabolic syndrome. Although it is difficult to eliminate the effects of body weight reduction and increased energy expenditure-some pleiotropic effects of exercise training-a number of studies involving either aerobic exercise training or resistance training programs showed ameliorations in NAFLD that are independent of the improvements in obesity and insulin resistance. In vivo studies have identified effects of exercise training on the liver, which may help to explain the "direct" or "independent" effect of exercise training on NAFLD. Exercise training increases peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) expression, improves mitochondrial function and leads to reduced hepatic steatosis, inflammation, fibrosis, and tumor genesis. Crosstalk between the liver and adipose tissue, skeletal muscle and the microbiome is also a possible mechanism for the effect of exercise training on NAFLD. Although numerous studies have reported benefits of exercise training on NAFLD, the optimal duration and intensity of exercise for the prevention or treatment of NAFLD have not been established. Maintaining adherence of patients with NAFLD to exercise training regimes is another issue to be resolved. The use of comprehensive analytical approaches to identify biomarkers such as hepatokines that specifically reflect the effect of exercise training on liver functions might help to monitor the effect of exercise on NAFLD, and thereby improve adherence of these patients to exercise training. Exercise training is a robust approach for alleviating the pathogenesis of NAFLD, although further clinical and experimental studies are required.
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Affiliation(s)
- Hirokazu Takahashi
- Division of Metabolism and Endocrinology, Faculty of Medicine, Saga University, Saga, Japan
- Liver Center, Saga University Hospital, Saga University, Saga, Japan
| | - Kazuhiko Kotani
- Division of Community and Family Medicine, Center for Community Medicine, Jichi Medical University, Shimotsuke, Japan
| | - Kenichi Tanaka
- Division of Metabolism and Endocrinology, Faculty of Medicine, Saga University, Saga, Japan
| | - Yuichiro Egucih
- Liver Center, Saga University Hospital, Saga University, Saga, Japan
| | - Keizo Anzai
- Division of Metabolism and Endocrinology, Faculty of Medicine, Saga University, Saga, Japan
- *Correspondence: Keizo Anzai
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166
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Kim KH, Lee MS. Pathogenesis of Nonalcoholic Steatohepatitis and Hormone-Based Therapeutic Approaches. Front Endocrinol (Lausanne) 2018; 9:485. [PMID: 30197624 PMCID: PMC6117414 DOI: 10.3389/fendo.2018.00485] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 08/06/2018] [Indexed: 12/12/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is an emerging global health problem and a potential risk factor for type 2 diabetes, cardiovascular disease, and chronic kidney disease. Nonalcoholic steatohepatitis (NASH), an advanced form of NAFLD, is a predisposing factor for development of cirrhosis and hepatocellular carcinoma. The increasing prevalence of NASH emphasizes the need for novel therapeutic approaches. Although therapeutic drugs against NASH are not yet available, fundamental insights into the pathogenesis of NASH have been made during the past few decades. Multiple therapeutic strategies have been developed and are currently being explored in clinical trials or preclinical testing. The pathogenesis of NASH involves multiple intracellular/extracellular events in various cell types in the liver or crosstalk events between the liver and other organs. Here, we review current findings and knowledge regarding the pathogenesis of NASH, focusing on the most recent advances. We also highlight hormone-based therapeutic approaches for treatment of NASH.
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Affiliation(s)
- Kook Hwan Kim
- Severance Biomedical Research Institute, Yonsei University College of Medicine, Seoul, South Korea
- *Correspondence: Kook Hwan Kim ;
| | - Myung-Shik Lee
- Severance Biomedical Research Institute, Yonsei University College of Medicine, Seoul, South Korea
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea
- Myung-Shik Lee
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167
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Pappachan JM, Babu S, Krishnan B, Ravindran NC. Non-alcoholic Fatty Liver Disease: A Clinical Update. J Clin Transl Hepatol 2017; 5:384-393. [PMID: 29226105 PMCID: PMC5719196 DOI: 10.14218/jcth.2017.00013] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 05/31/2017] [Accepted: 06/24/2017] [Indexed: 02/06/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is currently the most common chronic liver disease in developed countries because of the obesity epidemic. The disease increases liver-related morbidity and mortality, and often increases the risk for other comorbidities, such as type 2 diabetes and cardiovascular disease. Insulin resistance related to metabolic syndrome is the main pathogenic trigger that, in association with adverse genetic, humoral, hormonal and lifestyle factors, precipitates development of NAFLD. Biochemical markers and radiological imaging, along with liver biopsy in selected cases, help in diagnosis and prognostication. Intense lifestyle changes aiming at weight loss are the main therapeutic intervention to manage cases. Insulin sensitizers, antioxidants, lipid lowering agents, incretin-based drugs, weight loss medications, bariatric surgery and liver transplantation may be necessary for management in some cases along with lifestyle measures. This review summarizes the latest evidence on the epidemiology, natural history, pathogenesis, diagnosis and management of NAFLD.
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Affiliation(s)
- Joseph M Pappachan
- Department of Endocrinology, Diabetes & Metabolism, Royal Lancaster Infirmary, University Hospitals of Morecambe Bay NHS Trust, Lancaster, UK
| | - Shithu Babu
- Department of Medicine, Dorset County Hospital, Dorchester, UK
| | - Babu Krishnan
- Department of Gastroenterology & Hepatology, Royal Bournemouth Hospital, Bournemouth, UK
| | - Nishal C Ravindran
- Department of Gastroenterology & Hepatology, Hinchingbrooke Hospital, Hinchingbrooke, Huntingdon, UK
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168
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Nadeau BA, Conjeevaram H. The gut microbiome and nonalcoholic fatty liver disease. Clin Liver Dis (Hoboken) 2017; 10:116-119. [PMID: 30992769 PMCID: PMC6467119 DOI: 10.1002/cld.671] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 09/14/2017] [Accepted: 09/23/2017] [Indexed: 02/04/2023] Open
Affiliation(s)
- Brian A. Nadeau
- Division of Gastroenterology & Hepatology, Department of Internal MedicineUniversity of MichiganAnn ArborMI
| | - Hari Conjeevaram
- Division of Gastroenterology & Hepatology, Department of Internal MedicineUniversity of MichiganAnn ArborMI
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169
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Dorshow RB, Hall-Moore C, Shaikh N, Talcott MR, Faubion WA, Rogers TE, Shieh JJ, Debreczeny MP, Johnson JR, Dyer RB, Singh RJ, Tarr PI. Measurement of gut permeability using fluorescent tracer agent technology. Sci Rep 2017; 7:10888. [PMID: 28883476 PMCID: PMC5589723 DOI: 10.1038/s41598-017-09971-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 07/31/2017] [Indexed: 12/27/2022] Open
Abstract
The healthy gut restricts macromolecular and bacterial movement across tight junctions, while increased intestinal permeability accompanies many intestinal disorders. Dual sugar absorption tests, which measure intestinal permeability in humans, present challenges. Therefore, we asked if enterally administered fluorescent tracers could ascertain mucosal integrity, because transcutaneous measurement of differentially absorbed molecules could enable specimen-free evaluation of permeability. We induced small bowel injury in rats using high- (15 mg/kg), intermediate- (10 mg/kg), and low- (5 mg/kg) dose indomethacin. Then, we compared urinary ratios of enterally administered fluorescent tracers MB-402 and MB-301 to urinary ratios of sugar tracers lactulose and rhamnose. We also tested the ability of transcutaneous sensors to measure the ratios of absorbed fluorophores. Urinary fluorophore and sugar ratios reflect gut injury in an indomethacin dose dependent manner. The fluorophores generated smooth curvilinear ratio trajectories with wide dynamic ranges. The more chaotic sugar ratios had narrower dynamic ranges. Fluorophore ratios measured through the skin distinguished indomethacin-challenged from same day control rats. Enterally administered fluorophores can identify intestinal injury in a rat model. Fluorophore ratios are measureable through the skin, obviating drawbacks of dual sugar absorption tests. Pending validation, this technology should be considered for human use.
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Affiliation(s)
| | - Carla Hall-Moore
- Department of Pediatrics, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Nurmohammad Shaikh
- Department of Pediatrics, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Michael R Talcott
- Division of Comparative Medicine, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - William A Faubion
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN, USA
| | | | | | | | | | - Roy B Dyer
- Immunochemical Core Laboratory, Mayo Clinic, Rochester, MN, USA
| | | | - Phillip I Tarr
- Department of Pediatrics, Washington University in St. Louis School of Medicine, St. Louis, MO, USA.
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170
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Abstract
The gastrointestinal mucosa constitutes a critical barrier where millions of microbes and environmental antigens come in close contact with the host immune system. Intestinal barrier defects have been associated with a broad range of diseases and therefore denote a new therapeutic target. Areas covered: This review is based on an extensive literature search in PubMed of how the intestinal barrier contributes to health and as a trigger for disease. It discusses the anatomy of the intestinal barrier and explains the available methods to evaluate its function. Also reviewed is the importance of diet and lifestyle factors on intestinal barrier function, and three prototypes of chronic diseases (inflammatory bowel disease, celiac disease and nonalcoholic fatty liver disease) that have been linked to barrier defects are discussed. Expert commentary: The intestinal barrier has been investigated by various methods, but correlation of results across studies is difficult, representing a major shortcoming in the field. New upcoming techniques and research on the effect of barrier-restoring therapeutics may improve our current understanding of the gut barrier, and provide a step forward towards personalised medicine.
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171
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Gut-Liver Axis Derangement in Non-Alcoholic Fatty Liver Disease. CHILDREN-BASEL 2017; 4:children4080066. [PMID: 28767077 PMCID: PMC5575588 DOI: 10.3390/children4080066] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2017] [Revised: 07/18/2017] [Accepted: 07/21/2017] [Indexed: 02/06/2023]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the most frequent type of chronic liver disease in the pediatric age group, paralleling an obesity pandemic. A “multiple-hit” hypothesis has been invoked to explain its pathogenesis. The “first hit” is liver lipid accumulation in obese children with insulin resistance. In the absence of significant lifestyle modifications leading to weight loss and increased physical activity, other factors may act as “second hits” implicated in liver damage progression leading to more severe forms of inflammation and hepatic fibrosis. In this regard, the gut–liver axis (GLA) seems to play a central role. Principal players are the gut microbiota, its bacterial products, and the intestinal barrier. A derangement of GLA (namely, dysbiosis and altered intestinal permeability) may promote bacteria/bacterial product translocation into portal circulation, activation of inflammation via toll-like receptors signaling in hepatocytes, and progression from simple steatosis to non-alcoholic steato-hepatitis (NASH). Among other factors a relevant role has been attributed to the farnesoid X receptor, a nuclear transcriptional factor activated from bile acids chemically modified by gut microbiota (GM) enzymes. The individuation and elucidation of GLA derangement in NAFLD pathomechanisms is of interest at all ages and especially in pediatrics to identify new therapeutic approaches in patients recalcitrant to lifestyle changes. Specific targeting of gut microbiota via pre-/probiotic supplementation, feces transplantation, and farnesoid X receptor modulation appear promising.
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172
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Abstract
PURPOSE OF REVIEW Nonalcoholic fatty liver disease (NAFLD) is a liver disease with high prevalence in western countries. Progression from NAFLD to nonalcoholic steatohepatitis (NASH) occurs in 10-20%. NASH pathogenesis is multifactorial including genetic and environmental factors. The gut microbiota is involved in disease progression and its role is complex. RECENT FINDINGS NASH is associated with changes in the intestinal microbiota, although findings in recent studies are inconsistent. Dysbiosis can trigger intestinal inflammation and impair the gut barrier. Microbial products can now reach the liver, induce hepatic inflammation and contribute to NAFLD and NASH progression. As the gut microbiota is also involved in the regulation of metabolic pathways, metabolomic approaches identified unique metabolomic profiles in patients with NASH. Altered metabolite patterns can serve as biomarkers, whereas specific metabolites (such as ethanol) have been linked with disease progression. Modifying metabolic profiles might serve as new therapeutic microbiome-based approaches. SUMMARY In this review, we will highlight findings from the recent literature important to the gut-liver axis. We will predominantly focus on human studies with NASH.
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173
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Fedirko V, Tran HQ, Gewirtz AT, Stepien M, Trichopoulou A, Aleksandrova K, Olsen A, Tjønneland A, Overvad K, Carbonnel F, Boutron-Ruault MC, Severi G, Kühn T, Kaaks R, Boeing H, Bamia C, Lagiou P, Grioni S, Panico S, Palli D, Tumino R, Naccarati A, Peeters PH, Bueno-de-Mesquita HB, Weiderpass E, Castaño JMH, Barricarte A, Sánchez MJ, Dorronsoro M, Quirós JR, Agudo A, Sjöberg K, Ohlsson B, Hemmingsson O, Werner M, Bradbury KE, Khaw KT, Wareham N, Tsilidis KK, Aune D, Scalbert A, Romieu I, Riboli E, Jenab M. Exposure to bacterial products lipopolysaccharide and flagellin and hepatocellular carcinoma: a nested case-control study. BMC Med 2017; 15:72. [PMID: 28372583 PMCID: PMC5379669 DOI: 10.1186/s12916-017-0830-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 03/03/2017] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Leakage of bacterial products across the gut barrier may play a role in liver diseases which often precede the development of liver cancer. However, human studies, particularly from prospective settings, are lacking. METHODS We used a case-control study design nested within a large prospective cohort to assess the association between circulating levels of anti-lipopolysaccharide (LPS) and anti-flagellin immunoglobulin A (IgA) and G (IgG) (reflecting long-term exposures to LPS and flagellin, respectively) and risk of hepatocellular carcinoma. A total of 139 men and women diagnosed with hepatocellular carcinoma between 1992 and 2010 were matched to 139 control subjects. Multivariable rate ratios (RRs), including adjustment for potential confounders, hepatitis B/C positivity, and degree of liver dysfunction, were calculated with conditional logistic regression. RESULTS Antibody response to LPS and flagellin was associated with a statistically significant increase in the risk of hepatocellular carcinoma (highest vs. lowest quartile: RR = 11.76, 95% confidence interval = 1.70-81.40; P trend = 0.021). This finding did not vary substantially by time from enrollment to diagnosis, and did not change after adjustment for chronic infection with hepatitis B and C viruses. CONCLUSIONS These novel findings, based on exposures up to several years prior to diagnosis, support a role for gut-derived bacterial products in hepatocellular carcinoma development. Further study into the role of gut barrier failure and exposure to bacterial products in liver diseases is warranted.
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Affiliation(s)
- Veronika Fedirko
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA.
- Winship Cancer Institute, Emory University, Atlanta, GA, USA.
| | - Hao Quang Tran
- Center for Inflammation, Immunity, and Infection Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, 30303, USA
| | - Andrew T Gewirtz
- Center for Inflammation, Immunity, and Infection Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, 30303, USA
| | - Magdalena Stepien
- Section of Nutrition and Metabolism, International Agency for Research on Cancer (IARC-WHO), Lyon, France
| | - Antonia Trichopoulou
- Hellenic Health Foundation, 13 Kaisareias Street, Athens, GR-115 27, Greece
- Department of Hygiene, Epidemiology and Medical Statistics, WHO Collaborating Center for Nutrition and Health, Unit of Nutritional Epidemiology and Nutrition in Public Health, University of Athens Medical School, Athens, Greece
| | - Krasimira Aleksandrova
- Department of Epidemiology, German Institute of Human Nutrition Potsdam-Rehbruecke, Nutrition, Immunity and Metabolism Start-up Lab, Nuthetal, Germany
| | - Anja Olsen
- Danish Cancer Society Research Center, Copenhagen, Denmark
| | | | - Kim Overvad
- Section for Epidemiology, Department of Public Health, Aarhus University, Aarhus, Denmark
| | - Franck Carbonnel
- Université Paris-Saclay, Université Paris-Sud, UVSQ, CESP, INSERM, Villejuif, France
- Gustave Roussy, Villejuif, F-94805, France
- Department of Gastroenterology, Assistance Publique-Hôpitaux de Paris (AP-HP), University hospitals Paris-Sud, Site de Bicêtre, Paris Sud University, Paris XI, Le Kremlin Bicêtre, Villejuif, France
| | - Marie-Christine Boutron-Ruault
- Université Paris-Saclay, Université Paris-Sud, UVSQ, CESP, INSERM, Villejuif, France
- Gustave Roussy, Villejuif, F-94805, France
| | - Gianluca Severi
- Université Paris-Saclay, Université Paris-Sud, UVSQ, CESP, INSERM, Villejuif, France
- Gustave Roussy, Villejuif, F-94805, France
- Human Genetics Foundation (HuGeF), Torino, Italy
- Cancer Council Victoria and University of Melbourne, Melbourne, Australia
| | - Tilman Kühn
- Division of Cancer Epidemiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Rudolf Kaaks
- Division of Cancer Epidemiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Heiner Boeing
- Department of Epidemiology, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany
| | - Christina Bamia
- Hellenic Health Foundation, 13 Kaisareias Street, Athens, GR-115 27, Greece
- Department of Hygiene, Epidemiology and Medical Statistics, WHO Collaborating Center for Nutrition and Health, Unit of Nutritional Epidemiology and Nutrition in Public Health, University of Athens Medical School, Athens, Greece
| | - Pagona Lagiou
- Hellenic Health Foundation, 13 Kaisareias Street, Athens, GR-115 27, Greece
- Department of Hygiene, Epidemiology and Medical Statistics, WHO Collaborating Center for Nutrition and Health, Unit of Nutritional Epidemiology and Nutrition in Public Health, University of Athens Medical School, Athens, Greece
- Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA
| | - Sara Grioni
- Epidemiology and Prevention Unit Fondazione IRCCS Istituto Nazionale dei Tumori Via Venezian, 1 20133, Milano, Italy
| | - Salvatore Panico
- Dipartimento di Medicina Clinica Echirurgia Federico II University, Naples, Italy
| | - Domenico Palli
- Molecular and Nutritional Epidemiology Unit, Cancer Research and Prevention Institute - ISPO, Florence, Italy
| | - Rosario Tumino
- Cancer Registry and Histopathology Unit, "Civic -M.P. Arezzo" Hospital, ASP, Ragusa, Italy
| | - Alessio Naccarati
- Molecular and Genetic Epidemiology Unit, HuGeF, Human Genetics Foundation, Torino, Italy
| | - Petra H Peeters
- Department of Epidemiology, Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, the Netherlands
| | - H B Bueno-de-Mesquita
- Department for Determinants of Chronic Diseases (DCD), National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
- Department of Gastroenterology and Hepatology, University Medical Centre, Utrecht, The Netherlands
- Department of Epidemiology and Biostatistics, The School of Public Health, Imperial College London, London, UK
- Department of Social & Preventive Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Elisabete Weiderpass
- Department of Community Medicine, Faculty of Health Sciences, University of Tromsø, The Arctic University of Norway, Tromsø, Norway
- Department of Research, Cancer Registry of Norway, Institute of Population-Based Cancer Research, Oslo, Norway
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
- Genetic Epidemiology Group, Folkhälsan Research Center, Helsinki, Finland
| | - José María Huerta Castaño
- Department of Epidemiology, Murcia Regional Health Council, IMIB-Arrixaca, Murcia, Spain
- CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - Aurelio Barricarte
- CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
- Navarra Public Health Institute, Pamplona, Spain
- Navarra Institute for Health Research (IdiSNA), Pamplona, Spain
| | - María-José Sánchez
- CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
- Escuela Andaluza de Salud Pública. Instituto de Investigación Biosanitaria ibs.GRANADA. Hospitales Universitarios de Granada, Universidad de Granada, Granada, Spain
| | - Miren Dorronsoro
- CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
- Basque Regional Health Department, San Sebastian, Spain
| | | | - Antonio Agudo
- Unit of Nutrition, Environment and Cancer, Cancer Epidemiology Research Program, Catalan Institute of Oncology-IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Klas Sjöberg
- Department of Clinical Sciences, Lund University, Malmö, Sweden
- Department of Gastroenterology and Nutrition, Skåne University Hospital, Malmö, Sweden
| | - Bodil Ohlsson
- Department of Clinical Sciences, Division of Internal Medicine, Skåne University Hospital, Malmö, Lund University, Lund, Sweden
| | - Oskar Hemmingsson
- Department of Surgical and Perioperative Sciences, Kirurgcentrum, Norrlands Universitetssjukhus, Umeå, Sweden
| | - Mårten Werner
- Department of Medicine Sections for Hepatology and Gastroenterology, Umeå University Hospital, SE-90185, Umeå, Sweden
| | - Kathryn E Bradbury
- Cancer Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Kay-Tee Khaw
- Clinical Gerontology Unit, University of Cambridge School of Clinical Medicine, Cambridge, UK
| | - Nick Wareham
- MRC Epidemiology Unit, University of Cambridge, Cambridge, UK
| | - Konstantinos K Tsilidis
- Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
- Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, UK
| | - Dagfinn Aune
- Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, UK
| | - Augustin Scalbert
- Section of Nutrition and Metabolism, International Agency for Research on Cancer (IARC-WHO), Lyon, France
| | - Isabelle Romieu
- Section of Nutrition and Metabolism, International Agency for Research on Cancer (IARC-WHO), Lyon, France
| | - Elio Riboli
- Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, UK
| | - Mazda Jenab
- Section of Nutrition and Metabolism, International Agency for Research on Cancer (IARC-WHO), Lyon, France.
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Schumann M, Siegmund B, Schulzke JD, Fromm M. Celiac Disease: Role of the Epithelial Barrier. Cell Mol Gastroenterol Hepatol 2017; 3:150-162. [PMID: 28275682 PMCID: PMC5331784 DOI: 10.1016/j.jcmgh.2016.12.006] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 12/20/2016] [Indexed: 12/12/2022]
Abstract
In celiac disease (CD) a T-cell-mediated response to gluten is mounted in genetically predisposed individuals, resulting in a malabsorptive enteropathy histologically highlighted by villous atrophy and crypt hyperplasia. Recent data point to the epithelial layer as an under-rated hot spot in celiac pathophysiology to date. This overview summarizes current functional and genetic evidence on the role of the epithelial barrier in CD, consisting of the cell membranes and the apical junctional complex comprising sealing as well as ion and water channel-forming tight junction proteins and the adherens junction. Moreover, the underlying mechanisms are discussed, including apoptosis of intestinal epithelial cells, biology of intestinal stem cells, alterations in the apical junctional complex, transcytotic uptake of gluten peptides, and possible implications of a defective epithelial polarity. Current research is directed toward new treatment options for CD that are alternatives or complementary therapeutics to a gluten-free diet. Thus, strategies to target an altered epithelial barrier therapeutically also are discussed.
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Key Words
- Bmp, bone morphogenetic protein
- CBC, crypt base columnar cell
- CD, celiac disease
- Celiac Sprue
- EGF, epidermal growth factor
- Epithelial Polarity
- GFD, gluten-free diet
- GI, gastrointestinal
- GWAS, genome-wide association studies
- Gluten-Sensitive Enteropathy
- IEC, intestinal epithelial cell
- IL, interleukin
- MIC-A, major histocompatibility complex class I chain–related gene-A
- Partitioning-Defective Proteins
- SNP, single-nucleotide polymorphism
- TJ, tight junction
- Tight Junction
- ZO, zonula occludens
- aPKC, atypical protein kinase C
- α-Gliadin 33mer
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Affiliation(s)
- Michael Schumann
- Department of Gastroenterology, Infectious Diseases and Rheumatology, Campus Benjamin Franklin, Charité–Universitätsmedizin Berlin, Berlin, Germany
- Berlin Institute of Health, Berlin, Germany
- Berlin-Brandenburg School for Regenerative Therapies, Berlin, Germany
| | - Britta Siegmund
- Department of Gastroenterology, Infectious Diseases and Rheumatology, Campus Benjamin Franklin, Charité–Universitätsmedizin Berlin, Berlin, Germany
| | - Jörg D. Schulzke
- Institute of Clinical Physiology, Campus Benjamin Franklin, Charité–Universitätsmedizin Berlin, Berlin, Germany
| | - Michael Fromm
- Institute of Clinical Physiology, Campus Benjamin Franklin, Charité–Universitätsmedizin Berlin, Berlin, Germany
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175
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Abstract
A fundamental function of the intestinal epithelium is to act as a barrier that limits interactions between luminal contents such as the intestinal microbiota, the underlying immune system and the remainder of the body, while supporting vectorial transport of nutrients, water and waste products. Epithelial barrier function requires a contiguous layer of cells as well as the junctions that seal the paracellular space between epithelial cells. Compromised intestinal barrier function has been associated with a number of disease states, both intestinal and systemic. Unfortunately, most current clinical data are correlative, making it difficult to separate cause from effect in interpreting the importance of barrier loss. Some data from experimental animal models suggest that compromised epithelial integrity might have a pathogenic role in specific gastrointestinal diseases, but no FDA-approved agents that target the epithelial barrier are presently available. To develop such therapies, a deeper understanding of both disease pathogenesis and mechanisms of barrier regulation must be reached. Here, we review and discuss mechanisms of intestinal barrier loss and the role of intestinal epithelial barrier function in pathogenesis of both intestinal and systemic diseases. We conclude with a discussion of potential strategies to restore the epithelial barrier.
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Affiliation(s)
- Matthew A Odenwald
- Department of Pathology, The University of Chicago, 5841 South Maryland, Chicago, Illinois 60637, USA
| | - Jerrold R Turner
- Department of Pathology, The University of Chicago, 5841 South Maryland, Chicago, Illinois 60637, USA
- Departments of Pathology and Medicine (Gastroenterology), Brigham and Women's Hospital and Harvard Medical School, 20 Shattuck Street, Thorn 1428, Boston, Massachusetts 02115, USA
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Henkel AS, LeCuyer B, Olivares S, Green RM. Endoplasmic Reticulum Stress Regulates Hepatic Bile Acid Metabolism in Mice. Cell Mol Gastroenterol Hepatol 2016; 3:261-271. [PMID: 28275692 PMCID: PMC5331781 DOI: 10.1016/j.jcmgh.2016.11.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 11/01/2016] [Indexed: 12/31/2022]
Abstract
BACKGROUND & AIMS Cholestasis promotes endoplasmic reticulum (ER) stress in the liver, however, the effect of ER stress on hepatic bile acid metabolism is unknown. We aim to determine the effect of ER stress on hepatic bile acid synthesis and transport in mice. METHODS ER stress was induced pharmacologically in C57BL/6J mice and human hepatoma (HepG2) cells. The hepatic expression of genes controlling bile acid synthesis and transport was determined. To measure the activity of the primary bile acid synthetic pathway, the concentration of 7α-hydroxy-4-cholesten-3-1 was measured in plasma. RESULTS Induction of ER stress in mice and HepG2 cells rapidly suppressed the hepatic expression of the primary bile acid synthetic enzyme, cholesterol 7α-hydroxylase. Plasma levels of 7α-hydroxy-4-cholesten-3-1 were reduced in mice subjected to ER stress, indicating impaired bile acid synthesis. Induction of ER stress in mice and HepG2 cells increased expression of the bile salt export pump (adenosine triphosphate binding cassette [Abc]b11) and a bile salt efflux pump (Abcc3). The observed regulation of Cyp7a1, Abcb11, and Abcc3 occurred in the absence of hepatic inflammatory cytokine activation and was not dependent on activation of hepatic small heterodimer partner or intestinal fibroblast growth factor 15. Consistent with suppressed bile acid synthesis and enhanced bile acid export from hepatocytes, prolonged ER stress decreased the hepatic bile acid content in mice. CONCLUSIONS Induction of ER stress in mice suppresses bile acid synthesis and enhances bile acid removal from hepatocytes independently of established bile acid regulatory pathways. These data show a novel function of the ER stress response in regulating bile acid metabolism.
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Key Words
- 7α-Hydroxy-4-Cholesten-3-1
- ABC, adenosine triphosphate binding cassette
- Bile Acid Synthesis
- C4, 7α-hydroxy-4-cholesten-3-1
- CYP7A1, cholesterol 7α-hydroxylase
- Cyp7a1
- DMEM, Dulbecco's modified Eagle medium
- DMSO, dimethyl sulfoxide
- ER, endoplasmic reticulum
- ERK, extracellular signaling-regulated kinase
- FGF, fibroblast growth factor
- FXR, farnesoid X receptor
- IL, interleukin
- IRE1α, inositol requiring enzyme 1α
- JNK, c-Jun-N-terminal kinase
- NTCP, sodium/taurocholate cotransporter
- RIDD, regulated inositol requiring enzyme 1α–dependent messenger RNA decay
- SHP, small heterodimer partner
- UPR, unfolded protein response
- Unfolded Protein Response
- mRNA, messenger RNA
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Affiliation(s)
- Anne S. Henkel
- Correspondence Address correspondence to: Anne S. Henkel, MD, 320 East Superior Street, Tarry 15-705, Chicago, Illinois 60611. fax: (312) 908-9032.320 East Superior StreetTarry 15-705ChicagoIllinois 60611
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Bluemel S, Williams B, Knight R, Schnabl B. Precision medicine in alcoholic and nonalcoholic fatty liver disease via modulating the gut microbiota. Am J Physiol Gastrointest Liver Physiol 2016; 311:G1018-G1036. [PMID: 27686615 PMCID: PMC5206291 DOI: 10.1152/ajpgi.00245.2016] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 09/25/2016] [Indexed: 02/08/2023]
Abstract
Alcoholic liver disease (ALD) and nonalcoholic fatty liver disease (NAFLD) represent a major health burden in industrialized countries. Although alcohol abuse and nutrition play a central role in disease pathogenesis, preclinical models support a contribution of the gut microbiota to ALD and NAFLD. This review describes changes in the intestinal microbiota compositions related to ALD and NAFLD. Findings from in vitro, animal, and human studies are used to explain how intestinal pathology contributes to disease progression. This review summarizes the effects of untargeted microbiome modifications using antibiotics and probiotics on liver disease in animals and humans. While both affect humoral inflammation, regression of advanced liver disease or mortality has not been demonstrated. This review further describes products secreted by Lactobacillus- and microbiota-derived metabolites, such as fatty acids and antioxidants, that could be used for precision medicine in the treatment of liver disease. A better understanding of host-microbial interactions is allowing discovery of novel therapeutic targets in the gut microbiota, enabling new treatment options that restore the intestinal ecosystem precisely and influence liver disease. The modulation options of the gut microbiota and precision medicine employing the gut microbiota presented in this review have excellent prospects to improve treatment of liver disease.
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Affiliation(s)
- Sena Bluemel
- Department of Medicine, University of California San Diego, La Jolla, California
| | - Brandon Williams
- Department of Medicine, University of California San Diego, La Jolla, California
| | - Rob Knight
- Departments of Pediatrics and Computer Science and Engineering, University of California San Diego, La Jolla, California; and
| | - Bernd Schnabl
- Department of Medicine, University of California San Diego, La Jolla, California;
- Veterans Affairs San Diego Healthcare System, San Diego, California
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Gut Microbiota and the Liver: A Tale of 2 Cities: A Narrative View in 2 Acts. J Clin Gastroenterol 2016; 50 Suppl 2, Proceedings from the 8th Probiotics, Prebiotics & New Foods for Microbiota and Human Health meeting held in Rome, Italy on September 13-15, 2015:S183-S187. [PMID: 27741171 DOI: 10.1097/mcg.0000000000000699] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Microbes are mostly important for the digestion of food, the absorption of some micronutrients, and the production of vitamins. The microbiota stimulates lymphoid structures in the gastrointestinal mucosa and decrease pathogens by competing for nutrients and space. Bacterial translocation is defined as the escape of gut bacteria and their products through the intestinal mucosa to the outside of the intestine as portovenous or systemic circulation. This is induced by a leaky gut barrier. There is evidence for a role of intestinal permeability in the pathogenesis of nonalcoholic fatty liver disease. In the liver, bacterial products can bind to their specific pathogen recognition receptors on parenchymal and nonparenchymal cells, producing an inflammatory response and enhancing disease progression. When binding, bacterial products bind to their receptors, initiating intracellular signalling and inducing an inflammatory cascade, thus accelerating liver cell damage and fibrosis. However, the liver can also increase gut permeability, producing proinflammatory cytokines, and reversing them into the blood stream. Modification of the gut microbiota could lead to benefit in patients with liver disease. Nonabsorbable antibiotics (rifaximin) prevent and relieve overt encephalopathy. Probiotics alone are not capable of turning back overt encephalopathy, but could prevent its development. There is some evidence that probiotics could relent the progression of nonalcoholic liver disease, and possibly reverse steatosis. Antibiotics, such as fluoroquinolones, reduce the risk of development of the first episode of spontaneous bacterial peritonitis and mortality in cirrhotic patients.
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Rahman K, Desai C, Iyer SS, Thorn NE, Kumar P, Liu Y, Smith T, Neish AS, Li H, Tan S, Wu P, Liu X, Yu Y, Farris AB, Nusrat A, Parkos CA, Anania FA. Loss of Junctional Adhesion Molecule A Promotes Severe Steatohepatitis in Mice on a Diet High in Saturated Fat, Fructose, and Cholesterol. Gastroenterology 2016; 151:733-746.e12. [PMID: 27342212 PMCID: PMC5037035 DOI: 10.1053/j.gastro.2016.06.022] [Citation(s) in RCA: 217] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 05/19/2016] [Accepted: 06/10/2016] [Indexed: 02/08/2023]
Abstract
BACKGROUND & AIMS There is evidence from clinical studies that compromised intestinal epithelial permeability contributes to the development of nonalcoholic steatohepatitis (NASH), but the exact mechanisms are not clear. Mice with disruption of the gene (F11r) encoding junctional adhesion molecule A (JAM-A) have defects in intestinal epithelial permeability. We used these mice to study how disruption of the intestinal epithelial barrier contributes to NASH. METHODS Male C57BL/6 (control) or F11r(-/-) mice were fed a normal diet or a diet high in saturated fat, fructose, and cholesterol (HFCD) for 8 weeks. Liver and intestinal tissues were collected and analyzed by histology, quantitative reverse-transcription polymerase chain reaction, and flow cytometry. Intestinal epithelial permeability was assessed in mice by measuring permeability to fluorescently labeled dextran. The intestinal microbiota were analyzed using 16S ribosomal RNA sequencing. We also analyzed biopsy specimens from proximal colons of 30 patients with nonalcoholic fatty liver disease (NAFLD) and 19 subjects without NAFLD (controls) undergoing surveillance colonoscopy. RESULTS F11r(-/-) mice fed a HFCD, but not a normal diet, developed histologic and pathologic features of severe NASH including steatosis, lobular inflammation, hepatocellular ballooning, and fibrosis, whereas control mice fed a HFCD developed only modest steatosis. Interestingly, there were no differences in body weight, ratio of liver weight:body weight, or glucose homeostasis between control and F11r(-/-) mice fed a HFCD. In these mice, liver injury was associated with significant increases in mucosal inflammation, tight junction disruption, and intestinal epithelial permeability to bacterial endotoxins, compared with control mice or F11r(-/-) mice fed a normal diet. The HFCD led to a significant increase in inflammatory microbial taxa in F11r(-/-) mice, compared with control mice. Administration of oral antibiotics or sequestration of bacterial endotoxins with sevelamer hydrochloride reduced mucosal inflammation and restored normal liver histology in F11r(-/-) mice fed a HFCD. Protein and transcript levels of JAM-A were significantly lower in the intestinal mucosa of patients with NAFLD than without NAFLD; decreased expression of JAM-A correlated with increased mucosal inflammation. CONCLUSIONS Mice with defects in intestinal epithelial permeability develop more severe steatohepatitis after a HFCD than control mice, and colon tissues from patients with NAFLD have lower levels of JAM-A and higher levels of inflammation than subjects without NAFLD. These findings indicate that intestinal epithelial barrier function and microbial dysbiosis contribute to the development of NASH. Restoration of intestinal barrier integrity and manipulation of gut microbiota might be developed as therapeutic strategies for patients with NASH.
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Affiliation(s)
- Khalidur Rahman
- Division of Digestive Diseases, Department of Medicine, Yerkes National Primate Center, Emory University, Atlanta, Georgia; Atlanta VA Medical Center, Decatur, Georgia.
| | - Chirayu Desai
- P. D. Patel Institute of Applied Sciences, Charotar University of Science and Technology, Gujarat, India
| | - Smita S. Iyer
- Department of Microbiology and Immunology, Yerkes National Primate Center, Emory University, Atlanta, GA
| | - Natalie E. Thorn
- Division of Digestive Diseases, Department of Medicine, Yerkes National Primate Center, Emory University, Atlanta, GA
| | - Pradeep Kumar
- Division of Digestive Diseases, Department of Medicine, Yerkes National Primate Center, Emory University, Atlanta, GA
| | | | - Tekla Smith
- Division of Digestive Diseases, Department of Medicine, Yerkes National Primate Center, Emory University, Atlanta, GA,Atlanta VA medical center, Decatur, GA
| | - Andrew S. Neish
- Department of Pathology and Laboratory Medicine, Yerkes National Primate Center, Emory University, Atlanta, GA
| | - Hongliang Li
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China,Cardiovascular Research Institute, Renmin Hospital of Wuhan University, Wuhan, China
| | - Shiyun Tan
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Pengbo Wu
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Xiaoxiong Liu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China,Cardiovascular Research Institute, Renmin Hospital of Wuhan University, Wuhan, China
| | - Yuanjie Yu
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Alton B. Farris
- Department of Pathology and Laboratory Medicine, Yerkes National Primate Center, Emory University, Atlanta, GA
| | - Asma Nusrat
- Department of Pathology, The University of Michigan, Ann Arbor, MI
| | | | - Frank A. Anania
- Division of Digestive Diseases, Department of Medicine, Yerkes National Primate Center, Emory University, Atlanta, GA,Atlanta VA medical center, Decatur, GA,Corresponding Authors: Frank A. Anania, MD, FACP, AGAF, FAASLD, R. Bruce Logue Chair in Digestive Diseases, Professor of Medicine, 615 Michael Street, Suite 201, Atlanta, GA 30322, Phone: 404-712-2867, Fax: 404-727-5767, ; Khalidur Rahman, Ph.D., Post-Doctoral Fellow, 615 Michael Street, Suite 275, Atlanta, GA 30322, Phone: 404-712-2861, Fax: 404-727-5767,
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Cifarelli V, Ivanov S, Xie Y, Son NH, Saunders BT, Pietka TA, Shew TM, Yoshino J, Sundaresan S, Davidson NO, Goldberg IJ, Gelman AE, Zinselmeyer BH, Randolph GJ, Abumrad NA. CD36 deficiency impairs the small intestinal barrier and induces subclinical inflammation in mice. Cell Mol Gastroenterol Hepatol 2016; 3:82-98. [PMID: 28066800 PMCID: PMC5217470 DOI: 10.1016/j.jcmgh.2016.09.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND & AIMS CD36 has immuno-metabolic actions and is abundant in the small intestine on epithelial, endothelial and immune cells. We examined the role of CD36 in gut homeostasis using mice null for CD36 (CD36KO) and with CD36 deletion specific to enterocytes (Ent-CD36KO) or endothelial cells (EC-CD36KO). METHODS Intestinal morphology was evaluated using immunohistochemistry and electron microscopy (EM). Intestinal inflammation was determined from neutrophil infiltration and expression of cytokines, toll-like receptors and COX-2. Barrier integrity was assessed from circulating lipopolysaccharide (LPS) and dextran administered intragastrically. Epithelial permeability to luminal dextran was visualized using two photon microscopy. RESULTS The small intestines of CD36KO mice fed a chow diet showed several abnormalities including extracellular matrix (ECM) accumulation with increased expression of ECM proteins, evidence of neutrophil infiltration, inflammation and compromised barrier function. EM showed shortened desmosomes with decreased desmocollin 2 expression. Systemically, leukocytosis and neutrophilia were present together with 80% reduction of anti-inflammatory Ly6Clow monocytes. Bone marrow transplants supported the primary contribution of non-hematopoietic cells to the inflammatory phenotype. Specific deletion of endothelial but not of enterocyte CD36 reproduced many of the gut phenotypes of germline CD36KO mice including fibronectin deposition, increased interleukin 6, neutrophil infiltration, desmosome shortening and impaired epithelial barrier function. CONCLUSIONS CD36 loss results in chronic neutrophil infiltration of the gut, impairs barrier integrity and systemically causes subclinical inflammation. Endothelial cell CD36 deletion reproduces the major intestinal phenotypes. The findings suggest an important role of the endothelium in etiology of gut inflammation and loss of epithelial barrier integrity.
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Affiliation(s)
- Vincenza Cifarelli
- Department of Medicine, Center for Human Nutrition, Washington University School of Medicine, St Louis, Missouri,Reprint requests Address requests for reprints to: Nada A. Abumrad, PhD, or Vincenza Cifarelli, PhD, Department of Medicine, Center for Human Nutrition, Washington University School of Medicine, Campus Box 8031, St. Louis, Missouri 63110. fax: (314) 362-8230.Department of MedicineCenter for Human NutritionWashington University School of MedicineCampus Box 8031St. LouisMissouri 63110
| | - Stoyan Ivanov
- Department of Pathology and Immunology, Washington University School of Medicine, St Louis, Missouri
| | - Yan Xie
- Department of Medicine, Division of Gastroenterology, Washington University School of Medicine, St Louis, Missouri
| | - Ni-Huiping Son
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, New York University Langone Medical Center, New York, New York
| | - Brian T. Saunders
- Department of Pathology and Immunology, Washington University School of Medicine, St Louis, Missouri
| | - Terri A. Pietka
- Department of Medicine, Center for Human Nutrition, Washington University School of Medicine, St Louis, Missouri
| | - Trevor M. Shew
- Department of Medicine, Center for Human Nutrition, Washington University School of Medicine, St Louis, Missouri
| | - Jun Yoshino
- Department of Medicine, Center for Human Nutrition, Washington University School of Medicine, St Louis, Missouri
| | - Sinju Sundaresan
- Department of Medicine, Center for Human Nutrition, Washington University School of Medicine, St Louis, Missouri
| | - Nicholas O. Davidson
- Department of Medicine, Division of Gastroenterology, Washington University School of Medicine, St Louis, Missouri
| | - Ira J. Goldberg
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, New York University Langone Medical Center, New York, New York
| | - Andrew E. Gelman
- Department of Surgery, Washington University School of Medicine, St Louis, Missouri
| | - Bernd H. Zinselmeyer
- Department of Pathology and Immunology, Washington University School of Medicine, St Louis, Missouri
| | - Gwendalyn J. Randolph
- Department of Pathology and Immunology, Washington University School of Medicine, St Louis, Missouri
| | - Nada A. Abumrad
- Department of Medicine, Center for Human Nutrition, Washington University School of Medicine, St Louis, Missouri,Reprint requests Address requests for reprints to: Nada A. Abumrad, PhD, or Vincenza Cifarelli, PhD, Department of Medicine, Center for Human Nutrition, Washington University School of Medicine, Campus Box 8031, St. Louis, Missouri 63110. fax: (314) 362-8230.Department of MedicineCenter for Human NutritionWashington University School of MedicineCampus Box 8031St. LouisMissouri 63110
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Bashiardes S, Shapiro H, Rozin S, Shibolet O, Elinav E. Non-alcoholic fatty liver and the gut microbiota. Mol Metab 2016; 5:782-94. [PMID: 27617201 PMCID: PMC5004228 DOI: 10.1016/j.molmet.2016.06.003] [Citation(s) in RCA: 159] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 06/04/2016] [Accepted: 06/08/2016] [Indexed: 02/06/2023] Open
Abstract
Background Non-alcoholic fatty liver (NAFLD) is a common, multi-factorial, and poorly understood liver disease whose incidence is globally rising. NAFLD is generally asymptomatic and associated with other manifestations of the metabolic syndrome. Yet, up to 25% of NAFLD patients develop a progressive inflammatory liver disease termed non-alcoholic steatohepatitis (NASH) that may progress towards cirrhosis, hepatocellular carcinoma, and the need for liver transplantation. In recent years, several lines of evidence suggest that the gut microbiome represents a significant environmental factor contributing to NAFLD development and its progression into NASH. Suggested microbiome-associated mechanisms contributing to NAFLD and NASH include dysbiosis-induced deregulation of the gut endothelial barrier function, which facilitates systemic bacterial translocation, and intestinal and hepatic inflammation. Furthermore, increased microbiome-modulated metabolites such as lipopolysaccharides, short chain fatty acids (SCFAs), bile acids, and ethanol, may affect liver pathology through multiple direct and indirect mechanisms. Scope of review Herein, we discuss the associations, mechanisms, and clinical implications of the microbiome's contribution to NAFLD and NASH. Understanding these contributions to the development of fatty liver pathogenesis and its clinical course may serve as a basis for development of therapeutic microbiome-targeting approaches for treatment and prevention of NAFLD and NASH. Major conclusions Intestinal host–microbiome interactions play diverse roles in the pathogenesis and progression of NAFLD and NASH. Elucidation of the mechanisms driving these microbial effects on the pathogenesis of NAFLD and NASH may enable to identify new diagnostic and therapeutic targets of these common metabolic liver diseases. This article is part of a special issue on microbiota.
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Affiliation(s)
- Stavros Bashiardes
- Immunology Department, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Hagit Shapiro
- Immunology Department, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Shachar Rozin
- Immunology Department, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Oren Shibolet
- Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel; Department of Gastroenterology, Tel Aviv Medical Center, Tel Aviv 6423906, Israel
| | - Eran Elinav
- Immunology Department, Weizmann Institute of Science, 76100 Rehovot, Israel
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Hyperlipidemia and hepatitis in liver-specific CREB3L3 knockout mice generated using a one-step CRISPR/Cas9 system. Sci Rep 2016; 6:27857. [PMID: 27291420 PMCID: PMC4904192 DOI: 10.1038/srep27857] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 03/08/2016] [Indexed: 12/13/2022] Open
Abstract
cAMP responsive element binding protein 3-like 3 (CREB3L3), a transcription factor expressed in the liver and small intestine, governs fasting-response energy homeostasis. Tissue-specific CREB3L3 knockout mice have not been generated till date. To our knowledge, this is the first study using the one-step CRISPR/Cas9 system to generate CREB3L3 floxed mice and subsequently obtain liver- and small intestine-specific Creb3l3 knockout (LKO and IKO, respectively) mice. While LKO mice as well as global KO mice developed hypertriglyceridemia, LKO mice exhibited hypercholesterolemia in contrast to hypocholesterolemia in global KO mice. LKO mice demonstrated up-regulation of hepatic Srebf2 and its corresponding target genes. No phenotypic differences were observed between IKO and floxed mice. Severe liver injury was observed in LKO mice fed a methionine-choline deficient diet, a model for non-alcoholic steatohepatitis. These results provide new evidence regarding the hepatic CREB3L3 role in plasma triglyceride metabolism and hepatic and intestinal CREB3L3 contributions to cholesterol metabolism.
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183
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Arrese M, Cabrera D, Kalergis AM, Feldstein AE. Innate Immunity and Inflammation in NAFLD/NASH. Dig Dis Sci 2016; 61:1294-303. [PMID: 26841783 PMCID: PMC4948286 DOI: 10.1007/s10620-016-4049-x] [Citation(s) in RCA: 321] [Impact Index Per Article: 40.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 01/19/2016] [Indexed: 02/06/2023]
Abstract
Inflammation and hepatocyte injury and death are the hallmarks of nonalcoholic steatohepatitis (NASH), the progressive form of nonalcoholic fatty liver disease (NAFLD), which is a currently burgeoning public health problem. Innate immune activation is a key factor in triggering and amplifying hepatic inflammation in NAFLD/NASH. Thus, identification of the underlying mechanisms by which immune cells in the liver recognize cell damage signals or the presence of pathogens or pathogen-derived factors that activate them is relevant from a therapeutic perspective. In this review, we present new insights into the factors promoting the inflammatory response in NASH including sterile cell death processes resulting from lipotoxicity in hepatocytes as well as into the altered gut-liver axis function, which involves translocation of bacterial products into portal circulation as a result of gut leakiness. We further delineate the key immune cell types involved and how they recognize both damage-associated molecular patterns or pathogen-associated molecular patterns through binding of surface-expressed pattern recognition receptors, which initiate signaling cascades leading to injury amplification. The relevance of modulating these inflammatory signaling pathways as potential novel therapeutic strategies for the treatment of NASH is summarized.
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Affiliation(s)
- Marco Arrese
- Departmento de Gastroenterología, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Daniel Cabrera
- Departmento de Gastroenterología, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
- Departamento de Ciencias Químicas y Biológicas, Facultad de Salud, Universidad Bernardo O Higgins, Santiago, Chile
| | - Alexis M Kalergis
- Millenium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Ariel E Feldstein
- Department of Pediatrics, University of California San Diego (UCSD), San Diego, CA, USA.
- Rady Children's Hospital, San Diego, CA, USA.
- Division of Pediatric Gastroenterology, Hepatology, and Nutrition, UCSD, 3020 Children's Way, MC 5030, San Diego, CA, 92103-8450, USA.
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Abstract
PURPOSE OF REVIEW This article evaluates the current status of the gut barrier in gastrointestinal disorders. RECENT FINDINGS The gut barrier is a complex, multicomponent, interactive, and bidirectional entity that includes, but is not restricted to, the epithelial cell layer. Intestinal permeability, the phenomenon most readily and commonly studied, reflects just one (albeit an important one) function of the barrier that is intimately related to and interacts with luminal contents, including the microbiota. The mucosal immune response also influences barrier integrity; effects of inflammation per se must be accounted for in the interpretation of permeability studies in disease states. SUMMARY Although several aspects of barrier function can be assessed in man, one must be aware of exactly what a given test measures, as well as of its limitations. The temptation to employ results from a test of paracellular flux to imply a role for barrier dysfunction in disorders thought to be based on bacterial or macromolecular translocation must be resisted. Although changes in barrier function have been described in several gastrointestinal disorders, their primacy remains to be defined. At present, few studies support efficacy for an intervention that improves barrier function in altering the natural history of a disease process.
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Hellerbrand C, Schattenberg JM, Peterburs P, Lechner A, Brignoli R. The potential of silymarin for the treatment of hepatic disorders. CLINICAL PHYTOSCIENCE 2016. [DOI: 10.1186/s40816-016-0019-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
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The Gut Microbiota, Intestinal Permeability, Bacterial Translocation, and Nonalcoholic Fatty Liver Disease: What Comes First? Cell Mol Gastroenterol Hepatol 2015; 1:129-130. [PMID: 28210672 PMCID: PMC5301143 DOI: 10.1016/j.jcmgh.2015.01.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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