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Abstract
Recent progress has allowed a more comprehensive study of the gut microbiota. Gut microbiota helps in health maintenance and gut dysbiosis associates with chronic metabolic diseases. Modulation of short-chain fatty acids and choline bioavailability, lipoprotein lipase induction, alteration of bile acid profile, endogenous alcohol production, or liver inflammation secondary to endotoxemia result from gut dysbiosis. Modulation of the gut microbiota by pre/probiotics gives promising results in animal, but needs to be evaluated in human before use in clinical practice. Gut microbiota adds complexity to the pathophysiology of nonalcoholic fatty liver disease but represents an opportunity to discover new therapeutic targets.
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Affiliation(s)
- Jerome Boursier
- Hepato-Gastroenterology Department, University Hospital, 4 Larrey street, 49933 Angers Cedex 09, France; HIFIH Laboratory, UPRES 3859, SFR 4208, LUNAM University, Angers, France.
| | - Anna Mae Diehl
- Division of Gastroenterology, Department of Medicine, Duke University Medical Center, 595 LaSalle Street, Snyderman Building, Suite 1073, Durham, NC 27710, USA
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202
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Economopoulos KP, Ward NL, Phillips CD, Teshager A, Patel P, Mohamed MM, Hakimian S, Cox SB, Ahmed R, Moaven O, Kaliannan K, Alam SN, Haller JF, Goldstein AM, Bhan AK, Malo MS, Hodin RA. Prevention of antibiotic-associated metabolic syndrome in mice by intestinal alkaline phosphatase. Diabetes Obes Metab 2016; 18:519-27. [PMID: 26876427 PMCID: PMC5110215 DOI: 10.1111/dom.12645] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 02/02/2016] [Accepted: 02/09/2016] [Indexed: 12/20/2022]
Abstract
AIMS To examine whether co-administration of intestinal alkaline phosphatase (IAP) with antibiotics early in life may have a preventive role against metabolic syndrome (MetS) in mice. METHODS A total of 50 mice were allocated to four treatment groups after weaning. Mice were treated with azithromycin (AZT) ± IAP, or with no AZT ± IAP, for three intermittent 7-day cycles. After the last treatment course, the mice were administered a regular chow diet for 5 weeks and subsequently a high-fat diet for 5 weeks. Body weight, food intake, water intake, serum lipids, glucose levels and liver lipids were compared. 16S rRNA gene pyrosequencing was used to determine the differences in microbiome composition. RESULTS Exposure to AZT early in life rendered mice susceptible to MetS in adulthood. Co-administration of IAP with AZT completely prevented this susceptibility by decreasing total body weight, serum lipids, glucose levels and liver lipids to the levels of control mice. These effects of IAP probably occur as a result of changes in the composition of specific bacterial taxa at the genus and species levels (e.g. members of Anaeroplasma and Parabacteroides). CONCLUSIONS Co-administration of IAP with AZT early in life prevents mice from susceptibility to the later development of MetS. This effect is associated with alterations in the composition of the gut microbiota. IAP may represent a novel treatment against MetS in humans.
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Affiliation(s)
- K. P. Economopoulos
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - N. L. Ward
- Departments of Molecular Biology and Botany, University of Wyoming, WY 82071, USA
| | - C. D. Phillips
- Research and Testing Laboratory, Lubbock, TX 79407
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409
| | - A. Teshager
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - P. Patel
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - M. M. Mohamed
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - S. Hakimian
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - S. B. Cox
- Research and Testing Laboratory, Lubbock, TX 79407
| | - R. Ahmed
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - O. Moaven
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - K. Kaliannan
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - S. N. Alam
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - J. F. Haller
- Lipid Metabolism Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - A. M. Goldstein
- Department of Pediatric Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - A. K. Bhan
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - M. S. Malo
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - R. A. Hodin
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Corresponding author: Richard A. Hodin, MD, Department of Surgery, Massachusetts General Hospital, 15 Parkman Street, Boston, MA 02114; Telephone: (617) 724-2570; Fax: (617) 724-2574;
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203
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204
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Machado MV, Cortez-Pinto H. Diet, Microbiota, Obesity, and NAFLD: A Dangerous Quartet. Int J Mol Sci 2016; 17:481. [PMID: 27043550 PMCID: PMC4848937 DOI: 10.3390/ijms17040481] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 03/21/2016] [Accepted: 03/28/2016] [Indexed: 02/07/2023] Open
Abstract
Recently, the importance of the gut-liver-adipose tissue axis has become evident. Nonalcoholic fatty liver disease (NAFLD) is the hepatic disease of a systemic metabolic disorder that radiates from energy-surplus induced adiposopathy. The gut microbiota has tremendous influences in our whole-body metabolism, and is crucial for our well-being and health. Microorganisms precede humans in more than 400 million years and our guest flora evolved with us in order to help us face aggressor microorganisms, to help us maximize the energy that can be extracted from nutrients, and to produce essential nutrients/vitamins that we are not equipped to produce. However, our gut microbiota can be disturbed, dysbiota, and become itself a source of stress and injury. Dysbiota may adversely impact metabolism and immune responses favoring obesity and obesity-related disorders such as insulin resistance/diabetes mellitus and NAFLD. In this review, we will summarize the latest evidence of the role of microbiota/dysbiota in diet-induced obesity and NAFLD, as well as the potential therapeutic role of targeting the microbiota in this set.
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Affiliation(s)
- Mariana Verdelho Machado
- Departamento de Gastrenterologia, Hospital de Santa Maria, Centro Hospitalar Lisboa Norte (CHLN), 1649-035 Lisbon, Portugal.
- Laboratório de Nutrição, Faculdade de Medicina de Lisboa, Universidade de Lisboa, Alameda da Universidade, 1649-004 Lisboa, Portugal.
| | - Helena Cortez-Pinto
- Departamento de Gastrenterologia, Hospital de Santa Maria, Centro Hospitalar Lisboa Norte (CHLN), 1649-035 Lisbon, Portugal.
- Laboratório de Nutrição, Faculdade de Medicina de Lisboa, Universidade de Lisboa, Alameda da Universidade, 1649-004 Lisboa, Portugal.
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205
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He X, Ji G, Jia W, Li H. Gut Microbiota and Nonalcoholic Fatty Liver Disease: Insights on Mechanism and Application of Metabolomics. Int J Mol Sci 2016; 17:300. [PMID: 26999104 PMCID: PMC4813164 DOI: 10.3390/ijms17030300] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 02/14/2016] [Accepted: 02/17/2016] [Indexed: 02/07/2023] Open
Abstract
Gut microbiota are intricately involved in the development of obesity-related metabolic diseases such as nonalcoholic fatty liver disease (NAFLD), type 2 diabetes, and insulin resistance. In the current review, we discuss the role of gut microbiota in the development of NAFLD by focusing on the mechanisms of gut microbiota-mediated host energy metabolism, insulin resistance, regulation of bile acids and choline metabolism, as well as gut microbiota-targeted therapy. We also discuss the application of a metabolomic approach to characterize gut microbial metabotypes in NAFLD.
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Affiliation(s)
- Xuyun He
- Center for Chinese Medical Therapy and Systems Biology, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
| | - Guang Ji
- Institute of Digestive Disease, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
| | - Wei Jia
- Center for Chinese Medical Therapy and Systems Biology, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
- Center for Translational Medicine, and Shanghai Key Laboratory of Diabetes Mellitus, Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China.
| | - Houkai Li
- Center for Chinese Medical Therapy and Systems Biology, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
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206
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Boursier J, Mueller O, Barret M, Machado M, Fizanne L, Araujo-Perez F, Guy CD, Seed PC, Rawls JF, David LA, Hunault G, Oberti F, Calès P, Diehl AM. The severity of nonalcoholic fatty liver disease is associated with gut dysbiosis and shift in the metabolic function of the gut microbiota. Hepatology 2016; 63:764-75. [PMID: 4975935 PMCID: PMC4975935 DOI: 10.1002/hep.28356] [Citation(s) in RCA: 919] [Impact Index Per Article: 114.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 11/20/2015] [Indexed: 12/12/2022]
Abstract
UNLABELLED Several animal studies have emphasized the role of gut microbiota in nonalcoholic fatty liver disease (NAFLD). However, data about gut dysbiosis in human NAFLD remain scarce in the literature, especially studies including the whole spectrum of NAFLD lesions. We aimed to evaluate the association between gut dysbiosis and severe NAFLD lesions, that is, nonalcoholic steatohepatitis (NASH) and fibrosis, in a well-characterized population of adult NAFLD. Fifty-seven patients with biopsy-proven NAFLD were enrolled. Taxonomic composition of gut microbiota was determined using 16S ribosomal RNA gene sequencing of stool samples. Thirty patients had F0/F1 fibrosis stage at liver biopsy (10 with NASH), and 27 patients had significant F≥2 fibrosis (25 with NASH). Bacteroides abundance was significantly increased in NASH and F≥2 patients, whereas Prevotella abundance was decreased. Ruminococcus abundance was significantly higher in F≥2 patients. By multivariate analysis, Bacteroides abundance was independently associated with NASH and Ruminococcus with F≥2 fibrosis. Stratification according to the abundance of these two bacteria generated three patient subgroups with increasing severity of NAFLD lesions. Based on imputed metagenomic profiles, Kyoto Encyclopedia of Genes and Genomes pathways significantly related to NASH and fibrosis F≥2 were mostly related to carbohydrate, lipid, and amino acid metabolism. CONCLUSION NAFLD severity associates with gut dysbiosis and a shift in metabolic function of the gut microbiota. We identified Bacteroides as independently associated with NASH and Ruminococcus with significant fibrosis. Thus, gut microbiota analysis adds information to classical predictors of NAFLD severity and suggests novel metabolic targets for pre-/probiotics therapies.
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Affiliation(s)
- Jérôme Boursier
- Hepato-Gastroenterology Department, University Hospital, Angers, France, HIFIH Laboratory, UPRES 3859, SFR 4208, LUNAM University, Angers, France
| | - Olaf Mueller
- Center for Genomics of Microbial Systems, Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Matthieu Barret
- INRA, UMR1345 Institut de Recherches en Horticulture et Semences, SFR4207 QUASAV, F-49071, Beaucouzé, France
| | - Mariana Machado
- Division of Gastroenterology, Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Lionel Fizanne
- HIFIH Laboratory, UPRES 3859, SFR 4208, LUNAM University, Angers, France
| | - Felix Araujo-Perez
- Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Cynthia D. Guy
- Department of Pathology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Patrick C. Seed
- Center for Genomics of Microbial Systems, Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America, INRA, UMR1345 Institut de Recherches en Horticulture et Semences, SFR4207 QUASAV, F-49071, Beaucouzé, France, Division of Gastroenterology, Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, United States of America
| | - John F. Rawls
- Center for Genomics of Microbial Systems, Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Lawrence A. David
- Center for Genomics of Microbial Systems, Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Gilles Hunault
- HIFIH Laboratory, UPRES 3859, SFR 4208, LUNAM University, Angers, France
| | - Frédéric Oberti
- Hepato-Gastroenterology Department, University Hospital, Angers, France, HIFIH Laboratory, UPRES 3859, SFR 4208, LUNAM University, Angers, France
| | - Paul Calès
- Hepato-Gastroenterology Department, University Hospital, Angers, France, HIFIH Laboratory, UPRES 3859, SFR 4208, LUNAM University, Angers, France
| | - Anna Mae Diehl
- Division of Gastroenterology, Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
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207
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Boursier J, Mueller O, Barret M, Machado M, Fizanne L, Araujo-Perez F, Guy CD, Seed PC, Rawls JF, David LA, Hunault G, Oberti F, Calès P, Diehl AM. The severity of nonalcoholic fatty liver disease is associated with gut dysbiosis and shift in the metabolic function of the gut microbiota. Hepatology 2016. [PMID: 26600078 DOI: 10.1002/hep.28356 doi: 10.1002/hep.28356] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
UNLABELLED Several animal studies have emphasized the role of gut microbiota in nonalcoholic fatty liver disease (NAFLD). However, data about gut dysbiosis in human NAFLD remain scarce in the literature, especially studies including the whole spectrum of NAFLD lesions. We aimed to evaluate the association between gut dysbiosis and severe NAFLD lesions, that is, nonalcoholic steatohepatitis (NASH) and fibrosis, in a well-characterized population of adult NAFLD. Fifty-seven patients with biopsy-proven NAFLD were enrolled. Taxonomic composition of gut microbiota was determined using 16S ribosomal RNA gene sequencing of stool samples. Thirty patients had F0/F1 fibrosis stage at liver biopsy (10 with NASH), and 27 patients had significant F≥2 fibrosis (25 with NASH). Bacteroides abundance was significantly increased in NASH and F≥2 patients, whereas Prevotella abundance was decreased. Ruminococcus abundance was significantly higher in F≥2 patients. By multivariate analysis, Bacteroides abundance was independently associated with NASH and Ruminococcus with F≥2 fibrosis. Stratification according to the abundance of these two bacteria generated three patient subgroups with increasing severity of NAFLD lesions. Based on imputed metagenomic profiles, Kyoto Encyclopedia of Genes and Genomes pathways significantly related to NASH and fibrosis F≥2 were mostly related to carbohydrate, lipid, and amino acid metabolism. CONCLUSION NAFLD severity associates with gut dysbiosis and a shift in metabolic function of the gut microbiota. We identified Bacteroides as independently associated with NASH and Ruminococcus with significant fibrosis. Thus, gut microbiota analysis adds information to classical predictors of NAFLD severity and suggests novel metabolic targets for pre-/probiotics therapies.
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Affiliation(s)
- Jérôme Boursier
- Hepato-Gastroenterology Department, University Hospital, Angers, France.,HIFIH Laboratory, UPRES 3859, SFR 4208, LUNAM University, Angers, France
| | - Olaf Mueller
- Center for Genomics of Microbial Systems, Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC
| | - Matthieu Barret
- INRA, UMR1345 Institut de Recherches en Horticulture et Semences, SFR4207 QUASAV, Beaucouzé, France
| | - Mariana Machado
- Division of Gastroenterology, Department of Medicine, Duke University Medical Center, Durham, NC
| | - Lionel Fizanne
- HIFIH Laboratory, UPRES 3859, SFR 4208, LUNAM University, Angers, France
| | | | - Cynthia D Guy
- Department of Pathology, Duke University Medical Center, Durham, NC
| | - Patrick C Seed
- Center for Genomics of Microbial Systems, Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC.,Department of Pediatrics, Duke University Medical Center, Durham, NC
| | - John F Rawls
- Center for Genomics of Microbial Systems, Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC
| | - Lawrence A David
- Center for Genomics of Microbial Systems, Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC
| | - Gilles Hunault
- HIFIH Laboratory, UPRES 3859, SFR 4208, LUNAM University, Angers, France
| | - Frédéric Oberti
- Hepato-Gastroenterology Department, University Hospital, Angers, France.,HIFIH Laboratory, UPRES 3859, SFR 4208, LUNAM University, Angers, France
| | - Paul Calès
- Hepato-Gastroenterology Department, University Hospital, Angers, France.,HIFIH Laboratory, UPRES 3859, SFR 4208, LUNAM University, Angers, France
| | - Anna Mae Diehl
- Division of Gastroenterology, Department of Medicine, Duke University Medical Center, Durham, NC
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208
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Hu Y, Le Leu RK, Christophersen CT, Somashekar R, Conlon MA, Meng XQ, Winter JM, Woodman RJ, McKinnon R, Young GP. Manipulation of the gut microbiota using resistant starch is associated with protection against colitis-associated colorectal cancer in rats. Carcinogenesis 2016; 37:366-375. [PMID: 26905582 DOI: 10.1093/carcin/bgw019] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 02/05/2016] [Indexed: 12/13/2022] Open
Abstract
This study evaluated whether dietary resistant starch (RS) and green tea extract (GTE), which have anti-inflammatory and anticancer properties, protect against colitis-associated colorectal cancer (CAC) using a rat model, also investigated potential mechanisms of action of these agents including their effects on the gut microbiota. Rats were fed a control diet or diets containing 10% RS, 0.5% GTE or a combination of the two (RS + GTE). CAC was initiated with 2 weekly azoxymethane (AOM) injections (10mg/kg) followed by 2% dextran sodium sulphate in drinking water for 7 days after 2 weeks on diets. Rats were killed 20 weeks after the first AOM. Colon tissues and tumours were examined for histopathology by H&E, gene/protein expression by PCR and immunohistochemistry and digesta for analyses of fermentation products and microbiota populations. RS and RS + GTE (but not GTE) diets significantly (P< 0.05) decreased tumour multiplicity and adenocarcinoma formation, relative to the control diet. Effects of RS + GTE were not different from RS alone. RS diet caused significant shifts in microbial composition/diversity, with increases in Parabacteroides, Barnesiella, Ruminococcus, Marvinbryantia and Bifidobacterium as primary contributors to the shift. RS-containing diets increased short chain fatty acids (SCFA) and expression of the SCFA receptor GPR43 mRNA, and reduced inflammation (COX-2, NF-kB, TNF-α and IL-1β mRNA) and cell proliferation P< 0.05. GTE had no effect. This is the first study that demonstrates chemopreventive effects of RS (but not GTE) in a rodent CAC model, suggesting RS might have benefit to patients with ulcerative colitis who are at an increased risk of developing CRC.
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Affiliation(s)
- Ying Hu
- Flinders Centre for Innovation in Cancer , Flinders University of South Australia , Bedford Park , South Australia , Australia
| | - Richard K Le Leu
- Flinders Centre for Innovation in Cancer, Flinders University of South Australia, Bedford Park, South Australia, Australia.,CSIRO Food and Nutrition, Adelaide, South Australia, Australia
| | - Claus T Christophersen
- CSIRO Food and Nutrition, Adelaide, South Australia, Australia.,School of Medical and Health Science, Edith Cowan University, Western Australia, Australia, and
| | - Roshini Somashekar
- Flinders Centre for Innovation in Cancer , Flinders University of South Australia , Bedford Park , South Australia , Australia
| | - Michael A Conlon
- CSIRO Food and Nutrition , Adelaide , South Australia , Australia
| | - Xing Q Meng
- Biostatistics, Flinders Prevention, Promotion and Primary Health Care , General Practice , Flinders University of South Australia , Bedford Park , South Australia , Australia
| | - Jean M Winter
- Flinders Centre for Innovation in Cancer , Flinders University of South Australia , Bedford Park , South Australia , Australia
| | - Richard J Woodman
- Biostatistics, Flinders Prevention, Promotion and Primary Health Care , General Practice , Flinders University of South Australia , Bedford Park , South Australia , Australia
| | - Ross McKinnon
- Flinders Centre for Innovation in Cancer , Flinders University of South Australia , Bedford Park , South Australia , Australia
| | - Graeme P Young
- Flinders Centre for Innovation in Cancer , Flinders University of South Australia , Bedford Park , South Australia , Australia
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209
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Schröder T, Kucharczyk D, Bär F, Pagel R, Derer S, Jendrek ST, Sünderhauf A, Brethack AK, Hirose M, Möller S, Künstner A, Bischof J, Weyers I, Heeren J, Koczan D, Schmid SM, Divanovic S, Giles DA, Adamski J, Fellermann K, Lehnert H, Köhl J, Ibrahim S, Sina C. Mitochondrial gene polymorphisms alter hepatic cellular energy metabolism and aggravate diet-induced non-alcoholic steatohepatitis. Mol Metab 2016; 5:283-295. [PMID: 27069868 PMCID: PMC4812012 DOI: 10.1016/j.molmet.2016.01.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 01/18/2016] [Accepted: 01/25/2016] [Indexed: 02/07/2023] Open
Abstract
Objective Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease and is associated with an enhanced risk for liver and cardiovascular diseases and mortality. NAFLD can progress from simple hepatic steatosis to non-alcoholic steatohepatitis (NASH). However, the mechanisms predisposing to this progression remain undefined. Notably, hepatic mitochondrial dysfunction is a common finding in patients with NASH. Due to a lack of appropriate experimental animal models, it has not been evaluated whether this mitochondrial dysfunction plays a causative role for the development of NASH. Methods To determine the effect of a well-defined mitochondrial dysfunction on liver physiology at baseline and during dietary challenge, C57BL/6J-mtFVB/N mice were employed. This conplastic inbred strain has been previously reported to exhibit decreased mitochondrial respiration likely linked to a non-synonymous gene variation (nt7778 G/T) of the mitochondrial ATP synthase protein 8 (mt-ATP8). Results At baseline conditions, C57BL/6J-mtFVB/N mice displayed hepatic mitochondrial dysfunction characterized by decreased ATP production and increased formation of reactive oxygen species (ROS). Moreover, genes affecting lipid metabolism were differentially expressed, hepatic triglyceride and cholesterol levels were changed in these animals, and various acyl-carnitines were altered, pointing towards an impaired mitochondrial carnitine shuttle. However, over a period of twelve months, no spontaneous hepatic steatosis or inflammation was observed. On the other hand, upon dietary challenge with either a methionine and choline deficient diet or a western-style diet, C57BL/6J-mtFVB/N mice developed aggravated steatohepatitis as characterized by lipid accumulation, ballooning of hepatocytes and infiltration of immune cells. Conclusions We observed distinct metabolic alterations in mice with a mitochondrial polymorphism associated hepatic mitochondrial dysfunction. However, a second hit, such as dietary stress, was required to cause hepatic steatosis and inflammation. This study suggests a causative role of hepatic mitochondrial dysfunction in the development of experimental NASH. C57BL/6J-mtFVB/N mice (mt-ATP8, nt7778 G/T) display hepatic mitochondrial dysfunction. C57BL/6J-mtFVB/N mice display alterations in hepatic energy metabolism. C57BL/6J-mtFVB/N mice show no spontaneous hepatic steatosis or inflammation. C57BL/6J-mtFVB/N mice are susceptible to diet induced NASH. Study demonstrates causative role of mitochondrial dysfunction for NASH development.
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Key Words
- ALT, alanine aminotransferase
- AMP, adenosine monophosphate
- AMPK, AMP-activated proteinkinase
- ATP, adenosine triphosphate
- ATP8, ATP synthase protein 8
- Arg, arginine
- Asp, aspartic acid
- B6-mtB6, C57BL/6
- B6-mtFVB, C57BL/6-mtFVB/N
- C0, free dl-carnitine
- C16, hexadecanoyl-l-carntine
- C18, octadecanoyl-l-carnitine
- CD, control diet
- CD3, cluster of differentiation receptor 3
- CPT I, carnitine-palmitoyltransferase I
- CYP51A1, cytochrome P450, family 51, subfamily A, polypeptide 1
- GAPDH, glyceraldehyde 3-phosphate dehydrogenase
- Gr1, granulocyte differentiation antigen 1
- H&E, hematoxylin–eosin staining
- H2O2, hydrogen peroxide
- Hsd17b7, 17-beta-hydroxysteroid dehydrogenase type 7
- IDI1, isopentenyl-diphosphate delta isomerase 1
- IL, interleukin
- IPA, ingenuity pathway analysis
- KEGG, Kyoto Encyclopedia of Genes and Genomes
- Lipid metabolism
- Ly6G, lymphocyte antigen 6 complex, locus G
- MCDD, methionine and choline deficient diet
- MSMO1, methylsterol monooxygenase 1
- Met, methionine
- Mitochondrial dysfunction
- Mitochondrial gene polymorphism
- NAFL, non-alcoholic liver steatosis
- NAFLD
- NAFLD, non-alcoholic fatty liver disease
- NAS, NAFLD activity score
- NASH, non-alcoholic steatohepatitis
- ND3, NADH dehydrogenase subunit 3
- OCR, oxygen consumption rate
- OXPHOS, oxidative phosphorylation system
- PBS, phosphate buffered saline
- ROS, reactive oxygen species
- SNPs, single nucleotide polymorphisms
- SOD2, superoxide dismutase 2
- STRING, Search Tool for the Retrieval of Interacting Genes/Proteins
- Steatohepatitis
- TNFα
- TNFα, tumor necrosis factor alpha
- Tyr, tyrosine
- WD, western-style diet
- mt, mitochondrial
- pAMPK, phosphorylated AMP-activated proteinkinase
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Affiliation(s)
- Torsten Schröder
- University of Lübeck, Department of Medicine I, Ratzeburger Allee 160, D-23538 Lübeck, Germany; University of Lübeck, Institute for Systemic Inflammation Research, Ratzeburger Allee 160, D-23538 Lübeck, Germany
| | - David Kucharczyk
- University of Lübeck, Department of Medicine I, Ratzeburger Allee 160, D-23538 Lübeck, Germany
| | - Florian Bär
- University of Lübeck, Department of Medicine I, Ratzeburger Allee 160, D-23538 Lübeck, Germany
| | - René Pagel
- University of Lübeck, Department of Medicine I, Ratzeburger Allee 160, D-23538 Lübeck, Germany; University of Lübeck, Institute of Anatomy, Ratzeburger Allee 160, D-23538 Lübeck, Germany
| | - Stefanie Derer
- University of Lübeck, Department of Medicine I, Ratzeburger Allee 160, D-23538 Lübeck, Germany
| | - Sebastian Torben Jendrek
- University of Lübeck, Department of Medicine I, Ratzeburger Allee 160, D-23538 Lübeck, Germany; University of Lübeck, Institute of Anatomy, Ratzeburger Allee 160, D-23538 Lübeck, Germany
| | - Annika Sünderhauf
- University of Lübeck, Department of Medicine I, Ratzeburger Allee 160, D-23538 Lübeck, Germany
| | - Ann-Kathrin Brethack
- University of Lübeck, Department of Medicine I, Ratzeburger Allee 160, D-23538 Lübeck, Germany
| | - Misa Hirose
- University of Lübeck, The Lübeck Institute of Experimental Dermatology, Ratzeburger Allee 160, D-23538 Lübeck, Germany
| | - Steffen Möller
- University of Lübeck, The Lübeck Institute of Experimental Dermatology, Ratzeburger Allee 160, D-23538 Lübeck, Germany; Rostock University Medical Center, Institute for Biostatistics and Informatics in Medicine and Ageing Research, Ernst-Heydemann-Straße 8, D-18057 Rostock, Germany
| | - Axel Künstner
- University of Lübeck, The Lübeck Institute of Experimental Dermatology, Ratzeburger Allee 160, D-23538 Lübeck, Germany; Max Planck Institute for Evolutionary Biology, Guest Group Evolutionary Genomics, August-Thienemann-Straße 2, 24306 Plön, Germany
| | - Julia Bischof
- University of Lübeck, The Lübeck Institute of Experimental Dermatology, Ratzeburger Allee 160, D-23538 Lübeck, Germany
| | - Imke Weyers
- University of Lübeck, Institute of Anatomy, Ratzeburger Allee 160, D-23538 Lübeck, Germany
| | - Jörg Heeren
- University Hospital Hamburg-Eppendorf, Department of Biochemistry and Molecular Cell Biology, Martinistraße 52, D-20246 Hamburg, Germany
| | - Dirk Koczan
- University of Rostock, Institute of Immunology, Schillingallee 70, D-18057 Rostock, Germany
| | | | - Senad Divanovic
- Cincinnati Children's Hospital Research Foundation, University of Cincinnati, Division of Immunobiology, 3333 Burnet Avenue, Cincinnati, OH 45229-3026, USA
| | - Daniel Aaron Giles
- Cincinnati Children's Hospital Research Foundation, University of Cincinnati, Division of Immunobiology, 3333 Burnet Avenue, Cincinnati, OH 45229-3026, USA
| | - Jerzy Adamski
- Helmholtz Center, German Research Center for Environmental Health, Institute of Experimental Genetics, Genome Analysis Center, Ingolstaedter Landstraße 1, D-85764 Neuherberg, Germany; Technische Universität München, Lehrstuhl für Experimentelle Genetik, Liesel-Beckmann-Straße 4, 85350 Freising-Weihenstephan, Germany; German Center for Diabetes Research (DZD), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany
| | - Klaus Fellermann
- University of Lübeck, Department of Medicine I, Ratzeburger Allee 160, D-23538 Lübeck, Germany
| | - Hendrik Lehnert
- University of Lübeck, Department of Medicine I, Ratzeburger Allee 160, D-23538 Lübeck, Germany
| | - Jörg Köhl
- University of Lübeck, Institute for Systemic Inflammation Research, Ratzeburger Allee 160, D-23538 Lübeck, Germany; Cincinnati Children's Hospital Research Foundation, University of Cincinnati, Division of Immunobiology, 3333 Burnet Avenue, Cincinnati, OH 45229-3026, USA
| | - Saleh Ibrahim
- University of Lübeck, The Lübeck Institute of Experimental Dermatology, Ratzeburger Allee 160, D-23538 Lübeck, Germany
| | - Christian Sina
- University of Lübeck, Department of Medicine I, Ratzeburger Allee 160, D-23538 Lübeck, Germany.
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Sakai H, Shirakami Y, Shimizu M. Chemoprevention of obesity-related liver carcinogenesis by using pharmaceutical and nutraceutical agents. World J Gastroenterol 2016; 22:394-406. [PMID: 26755885 PMCID: PMC4698502 DOI: 10.3748/wjg.v22.i1.394] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 10/14/2015] [Accepted: 11/24/2015] [Indexed: 02/06/2023] Open
Abstract
Obesity and its related metabolic disorders are serious health problems worldwide, and lead to various health-related complications, including cancer. Among human cancers, hepatocellular carcinoma (HCC) is one of the most common malignancies affected by obesity. Therefore, obesity and its related disorders might be a key target for the prevention of HCC. Recently, new research indicates that the molecular abnormalities associated with obesity, including insulin resistance/hyperinsulinemia, chronic inflammation, adipokine imbalance, and oxidative stress, are possible molecular mechanisms underlying the pathogenesis of obesity-related hepatocarcinogenesis. Green tea catechins and branched-chain amino acids, both of which are classified as nutraceutical agents, have been reported to prevent obesity-related HCC development by improving metabolic abnormalities. The administration of acyclic retinoid, a pharmaceutical agent, reduced the incidence of HCC in obese and diabetic mice, and was also associated with improvements in insulin resistance and chronic inflammation. In this article, we review the detailed molecular mechanisms that link obesity to the development of HCC in obese individuals. We also summarize recent evidence from experimental and clinical studies using either nutraceutical or pharmaceutical agents, and suggest that nutraceutical and pharmaceutical approaches targeting metabolic abnormalities might be a promising strategy to prevent the development of obesity-related HCC.
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211
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Lambert JE, Parnell JA, Eksteen B, Raman M, Bomhof MR, Rioux KP, Madsen KL, Reimer RA. Gut microbiota manipulation with prebiotics in patients with non-alcoholic fatty liver disease: a randomized controlled trial protocol. BMC Gastroenterol 2015; 15:169. [PMID: 26635079 PMCID: PMC4669628 DOI: 10.1186/s12876-015-0400-5] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 11/25/2015] [Indexed: 02/08/2023] Open
Abstract
Background Evidence for the role of the gut microbiome in the pathogenesis of non-alcoholic fatty liver disease (NAFLD) is emerging. Strategies to manipulate the gut microbiota towards a healthier community structure are actively being investigated. Based on their ability to favorably modulate the gut microbiota, prebiotics may provide an inexpensive yet effective dietary treatment for NAFLD. Additionally, prebiotics have established benefits for glucose control and potentially weight control, both advantageous in managing fatty liver disease. Our objective is to evaluate the effects of prebiotic supplementation, adjunct to those achieved with diet-induced weight loss, on heptic injury and liver fat, the gut microbiota, inflammation, glucose tolerance, and satiety in patients with NAFLD. Methods/design In a double blind, placebo controlled, parallel group study, adults (BMI ≥25) with confirmed NAFLD will be randomized to either a 16 g/d prebiotic supplemented group or isocaloric placebo group for 24 weeks (n = 30/group). All participants will receive individualized dietary counseling sessions with a registered dietitian to achieve 10 % weight loss. Primary outcome measures include change in hepatic injury (fibrosis and inflammation) and liver fat. Secondary outcomes include change in body composition, appetite and dietary adherence, glycemic and insulinemic responses and inflammatory cytokines. Mechanisms related to prebiotic-induced changes in gut microbiota (shot-gun sequencing) and their metabolic by-products (volatile organic compounds) and de novo lipogenesis (using deuterium incorporation) will also be investigated. Discussion There are currently no medications or surgical procedures approved for the treatment of NAFLD and weight loss via lifestyle modification remains the cornerstone of current care recommendations. Given that prebiotics target multiple metabolic impairments associated with NAFLD, investigating their ability to modulate the gut microbiota and hepatic health in patients with NAFLD is warranted. Trial registration ClinicalTrials.gov (NCT02568605) Registered 30 September 2015
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Affiliation(s)
- Jennifer E Lambert
- Faculty of Kinesiology, University of Calgary, 2500 University Dr. NW, Calgary, AB, T2N 1N4, Canada.
| | - Jill A Parnell
- Health and Physical Education, Mount Royal University, 4825 Mount Royal Gate SW, Calgary, AB, T3E 6K6, Canada.
| | - Bertus Eksteen
- Snyder Institute for Chronic Diseases, Health Research and Innovation Center, University of Calgary, 3280 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada. .,Division of Gastroenterology and Hepatology, Department of Medicine, University of Calgary, 3280 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada.
| | - Maitreyi Raman
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Calgary, 3280 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada.
| | - Marc R Bomhof
- Faculty of Kinesiology, University of Calgary, 2500 University Dr. NW, Calgary, AB, T2N 1N4, Canada.
| | - Kevin P Rioux
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Calgary, 3280 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada. .,Department of Microbiology and Infectious Diseases, University of Calgary, 1863 Health Sciences Centre, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada.
| | - Karen L Madsen
- Division of Gastroenterology, Centre of Excellence for Gastrointestinal Inflammation and Immunity Research, 7-142 Katz Group-Rexall Centre, University of Alberta, Edmonton, AB, T6G 2C2, Canada.
| | - Raylene A Reimer
- Faculty of Kinesiology, University of Calgary, 2500 University Dr. NW, Calgary, AB, T2N 1N4, Canada. .,Department of Biochemistry & Molecular Biology, Cumming School of Medicine, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada.
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Abstract
BACKGROUND Non-alcoholic fatty liver disease (NAFLD) is a common disorder with poorly understood pathogenesis. Beyond environmental and genetic factors, cumulative data support the causative role of gut microbiota in disease development and progression. DATA SOURCE We performed a PubMed literature search with the following key words: "non-alcoholic fatty liver disease", "non-alcoholic steatohepatitis", "fatty liver", "gut microbiota" and "microbiome", to review the data implicating gut microbiota in NAFLD development and progression. RESULTS Recent metagenomic studies revealed differences in the phylum and genus levels between patients with fatty liver and healthy controls. While bacteroidetes and firmicutes remain the dominant phyla among NAFLD patients, their proportional abundance and genera detection vary among different studies. New techniques indicate a correlation between the methanogenic archaeon (methanobrevibacter smithii) and obesity, while the bacterium akkermanshia municiphila protects against metabolic syndrome. Among NAFLD patients, small intestinal bacterial overgrowth detected by breath tests might induce gut microbiota and host interactions, facilitating disease development. CONCLUSIONS There is evidence that gut microbiota participates in NAFLD development through, among others, obesity induction, endogenous ethanol production, inflammatory response triggering and alterations in choline metabolism. Further studies with emerging techniques are needed to further elucidate the microbiome and host crosstalk in NAFLD pathogenesis.
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Affiliation(s)
- Paraskevas Gkolfakis
- Hepatogastroenterology Unit, Second Department of Internal Medicine and Research Institute, Attikon University General Hospital, Medical School, Athens University, 124 62 Athens, Greece.
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Wieland A, Frank DN, Harnke B, Bambha K. Systematic review: microbial dysbiosis and nonalcoholic fatty liver disease. Aliment Pharmacol Ther 2015; 42:1051-63. [PMID: 26304302 DOI: 10.1111/apt.13376] [Citation(s) in RCA: 148] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 01/11/2015] [Accepted: 07/29/2015] [Indexed: 12/16/2022]
Abstract
BACKGROUND The human intestinal microbiota is a key regulator of host metabolic and immune functions and alterations in the microbiome ('dysbiosis') have been implicated in several human diseases. Because of the anatomical links between the intestines and the liver, dysbiosis may also disrupt hepatic function and thereby contribute to the pathogenesis of nonalcoholic fatty liver disease (NAFLD). AIM To perform a comprehensive review of the medical literature investigating associations between intestinal dysbiosis and NAFLD, with a particular emphasis on studies that characterise the microbiome in NAFLD. METHODS We conducted a search of PubMed, Embase, and Web of Science using multiple search terms including: 'NAFLD, NASH, fatty liver, steatohepatitis' combined with 'metagenome, microbiom*, microbiota*, fecal flora, intestinal flora, gut bacteria'. Results were manually reviewed and studies selected based on relevance to intestinal microbiota and NAFLD. We also included studies that addressed potential mechanistic models of pathways linking the dysbiosis to NAFLD. RESULTS Nine studies (five human and four animal models) were identified in our search that assessed associations between specific intestinal microbiota composition and NAFLD. We reviewed and summarised the results of additional investigations that more broadly addressed the mechanisms by which the microbiome may impact NAFLD pathogenesis. CONCLUSIONS Investigations in humans and animals demonstrate associations between intestinal dysbiosis and NAFLD; however, causality has not been proven and mechanistic links require further delineation. As the field of microbiome research matures in techniques and study design, more detailed insights into NAFLD pathogenesis and its associations with the intestinal microbiota will be elucidated.
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Affiliation(s)
- A Wieland
- Division of Gastroenterology and Hepatology, University of Colorado Denver, Aurora, CO, USA
| | - D N Frank
- Division of Infectious Diseases and Microbiome Research Consortium, University of Colorado Denver, Aurora, CO, USA
| | - B Harnke
- University of Colorado Health Science Library, Aurora, CO, USA
| | - K Bambha
- Division of Gastroenterology and Hepatology, University of Colorado Denver, Aurora, CO, USA
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214
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Gut Microbiota and Host Reaction in Liver Diseases. Microorganisms 2015; 3:759-91. [PMID: 27682116 PMCID: PMC5023261 DOI: 10.3390/microorganisms3040759] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 10/08/2015] [Accepted: 10/21/2015] [Indexed: 02/07/2023] Open
Abstract
Although alcohol feeding produces evident intestinal microbial changes in animals, only some alcoholics show evident intestinal dysbiosis, a decrease in Bacteroidetes and an increase in Proteobacteria. Gut dysbiosis is related to intestinal hyperpermeability and endotoxemia in alcoholic patients. Alcoholics further exhibit reduced numbers of the beneficial Lactobacillus and Bifidobacterium. Large amounts of endotoxins translocated from the gut strongly activate Toll-like receptor 4 in the liver and play an important role in the progression of alcoholic liver disease (ALD), especially in severe alcoholic liver injury. Gut microbiota and bacterial endotoxins are further involved in some of the mechanisms of nonalcoholic fatty liver disease (NAFLD) and its progression to nonalcoholic steatohepatitis (NASH). There is experimental evidence that a high-fat diet causes characteristic dysbiosis of NAFLD, with a decrease in Bacteroidetes and increases in Firmicutes and Proteobacteria, and gut dysbiosis itself can induce hepatic steatosis and metabolic syndrome. Clinical data support the above dysbiosis, but the details are variable. Intestinal dysbiosis and endotoxemia greatly affect the cirrhotics in relation to major complications and prognosis. Metagenomic approaches to dysbiosis may be promising for the analysis of deranged host metabolism in NASH and cirrhosis. Management of dysbiosis may become a cornerstone for the future treatment of liver diseases.
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215
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Stadlbauer V, Leber B, Lemesch S, Trajanoski S, Bashir M, Horvath A, Tawdrous M, Stojakovic T, Fauler G, Fickert P, Högenauer C, Klymiuk I, Stiegler P, Lamprecht M, Pieber TR, Tripolt NJ, Sourij H. Lactobacillus casei Shirota Supplementation Does Not Restore Gut Microbiota Composition and Gut Barrier in Metabolic Syndrome: A Randomized Pilot Study. PLoS One 2015; 10:e0141399. [PMID: 26509793 PMCID: PMC4625062 DOI: 10.1371/journal.pone.0141399] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 10/05/2015] [Indexed: 12/19/2022] Open
Abstract
UNLABELLED Metabolic syndrome is associated with disturbances in gut microbiota composition. We aimed to investigate the effect of Lactobacillus casei Shirota (LcS) on gut microbiota composition, gut barrier integrity, intestinal inflammation and serum bile acid profile in metabolic syndrome. In a single-centre, prospective, randomised controlled pilot study, 28 subjects with metabolic syndrome received either LcS for 12 weeks (n = 13) or no LcS (n = 15). Data were compared to healthy controls (n = 16). Gut microbiota composition was characterised from stool using 454 pyrosequencing of 16S rRNA genes. Serum bile acids were quantified by tandem mass spectrometry. Zonulin and calprotectin were measured in serum and stool by ELISA. Bacteroidetes/Firmicutes ratio was significantly higher in healthy controls compared to metabolic syndrome but was not influenced by LcS. LcS supplementation led to enrichment of Parabacteroides. Zonulin and calprotectin were increased in metabolic syndrome stool samples but not influenced by LcS supplementation. Serum bile acids were similar to controls and not influenced by LcS supplementation. Metabolic syndrome is associated with a higher Bacteroidetes/Firmicutes ratio and gut barrier dysfunction but LcS was not able to change this. LcS administration was associated with subtle microbiota changes at genus level. TRIAL REGISTRATION ClinicalTrials.gov NCT01182844.
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Affiliation(s)
- Vanessa Stadlbauer
- Medical University of Graz, Division of Gastroenterology and Hepatology, Graz, Austria
| | - Bettina Leber
- Medical University of Graz, Division of Transplantation Surgery, Graz, Austria
| | - Sandra Lemesch
- Medical University of Graz, Division of Gastroenterology and Hepatology, Graz, Austria
| | | | - Mina Bashir
- Medical University of Graz, Division of Endocrinology and Metabolism, Graz, Austria
| | - Angela Horvath
- Medical University of Graz, Division of Gastroenterology and Hepatology, Graz, Austria
| | - Monika Tawdrous
- Medical University of Graz, Division of Gastroenterology and Hepatology, Graz, Austria
| | - Tatjana Stojakovic
- Medical University of Graz, Clinical Institute of Medical and Chemical Laboratory Diagnostics, Graz, Austria
| | - Günter Fauler
- Medical University of Graz, Clinical Institute of Medical and Chemical Laboratory Diagnostics, Graz, Austria
| | - Peter Fickert
- Medical University of Graz, Division of Gastroenterology and Hepatology, Graz, Austria
| | - Christoph Högenauer
- Medical University of Graz, Division of Gastroenterology and Hepatology, Graz, Austria
| | | | - Philipp Stiegler
- Medical University of Graz, Division of Transplantation Surgery, Graz, Austria
| | - Manfred Lamprecht
- Medical University of Graz, Institute of Physiological Chemistry, Centre for Physiological Medicine, Graz, Austria
| | - Thomas R. Pieber
- Medical University of Graz, Division of Endocrinology and Metabolism, Graz, Austria
- Centre for Biomarker Research in Medicine (CBmed), Graz, Austria
| | - Norbert J. Tripolt
- Medical University of Graz, Division of Endocrinology and Metabolism, Graz, Austria
| | - Harald Sourij
- Medical University of Graz, Division of Endocrinology and Metabolism, Graz, Austria
- Centre for Biomarker Research in Medicine (CBmed), Graz, Austria
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216
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Mechanistic link between nonalcoholic fatty liver disease and cardiometabolic disorders. Int J Cardiol 2015; 201:408-14. [PMID: 26310987 DOI: 10.1016/j.ijcard.2015.08.107] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 07/22/2015] [Accepted: 08/09/2015] [Indexed: 02/08/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a chronic condition characterized by fat accumulation combined with low-grade inflammation in the liver. A large body of clinical and experimental data shows that increased flux of free fatty acids from increased visceral adipose tissue can lead to NAFLD related with insulin resistance. Thus, individuals with obesity, insulin resistance, and dyslipidemia are at the greatest risk of developing NAFLD. Conversely, NAFLD is one of the phenotypes of insulin resistance or metabolic syndrome. Many researchers have discovered a close association between NAFLD and insulin resistance, and focused on the role of NAFLD in the development of type 2 diabetes. Further, substantial evidence has suggested the association between NAFLD and cardiovascular disease (CVD). In the current review, we provide a plausible mechanistic link between NAFLD and CVD and the potential of the former as a therapeutic target based on pathophysiology. We also discuss in detail about the role of insulin resistance, oxidative stress, low-grade inflammation, abnormal lipid metabolism, gut microbiota, changes of biomarkers, and genetic predisposition in the pathological linking between NAFLD and cardiometabolic disorders.
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217
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Frank DN, Bales ES, Monks J, Jackman MJ, MacLean PS, Ir D, Robertson CE, Orlicky DJ, McManaman JL. Perilipin-2 Modulates Lipid Absorption and Microbiome Responses in the Mouse Intestine. PLoS One 2015; 10:e0131944. [PMID: 26147095 PMCID: PMC4493139 DOI: 10.1371/journal.pone.0131944] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 06/08/2015] [Indexed: 02/06/2023] Open
Abstract
Obesity and its co-morbidities, such as fatty liver disease, are increasingly prevalent worldwide health problems. Intestinal microorganisms have emerged as critical factors linking diet to host physiology and metabolic function, particularly in the context of lipid homeostasis. We previously demonstrated that deletion of the cytoplasmic lipid drop (CLD) protein Perilipin-2 (Plin2) in mice largely abrogates long-term deleterious effects of a high fat (HF) diet. Here we test the hypotheses that Plin2 function impacts the earliest steps of HF diet-mediated pathogenesis as well as the dynamics of diet-associated changes in gut microbiome diversity and function. WT and perilipin-2 null mice raised on a standard chow diet were randomized to either low fat (LF) or HF diets. After four days, animals were assessed for changes in physiological (body weight, energy balance, and fecal triglyceride levels), histochemical (enterocyte CLD content), and fecal microbiome parameters. Plin2-null mice had significantly lower respiratory exchange ratios, diminished frequencies of enterocyte CLDs, and increased fecal triglyceride levels compared with WT mice. Microbiome analyses, employing both 16S rRNA profiling and metagenomic deep sequencing, indicated that dietary fat content and Plin2 genotype were significantly and independently associated with gut microbiome composition, diversity, and functional differences. These data demonstrate that Plin2 modulates rapid effects of diet on fecal lipid levels, enterocyte CLD contents, and fuel utilization properties of mice that correlate with structural and functional differences in their gut microbial communities. Collectively, the data provide evidence of Plin2 regulated intestinal lipid uptake, which contributes to rapid changes in the gut microbial communities implicated in diet-induced obesity.
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Affiliation(s)
- Daniel N. Frank
- Division of Infectious Disease, University of Colorado School of Medicine, Aurora, Colorado, United States of America
- Microbiome Research Consortium, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Elise S. Bales
- Division of Basic Reproductive Sciences, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Jenifer Monks
- Division of Basic Reproductive Sciences, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Matthew J. Jackman
- Division of Endocrinology and Metabolism, University of Colorado School of Medicine, Aurora, Colorado, United States of America
- The Center for Human Nutrition, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Paul S. MacLean
- Division of Endocrinology and Metabolism, University of Colorado School of Medicine, Aurora, Colorado, United States of America
- The Center for Human Nutrition, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Diana Ir
- Division of Infectious Disease, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Charles E. Robertson
- Division of Infectious Disease, University of Colorado School of Medicine, Aurora, Colorado, United States of America
- Microbiome Research Consortium, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - David J. Orlicky
- Department of Pathology, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - James L. McManaman
- Division of Basic Reproductive Sciences, University of Colorado School of Medicine, Aurora, Colorado, United States of America
- The Center for Human Nutrition, University of Colorado School of Medicine, Aurora, Colorado, United States of America
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218
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Kirpich IA, Marsano LS, McClain CJ. Gut-liver axis, nutrition, and non-alcoholic fatty liver disease. Clin Biochem 2015; 48:923-30. [PMID: 26151226 DOI: 10.1016/j.clinbiochem.2015.06.023] [Citation(s) in RCA: 205] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Revised: 06/22/2015] [Accepted: 06/27/2015] [Indexed: 02/08/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) represents a spectrum of diseases involving hepatic fat accumulation, inflammation with the potential progression to fibrosis and cirrhosis over time. NAFLD is often associated with obesity, insulin resistance, and diabetes. The interactions between the liver and the gut, the so-called "gut-liver axis", play a critical role in NAFLD onset and progression. Compelling evidence links the gut microbiome, intestinal barrier integrity, and NAFLD. The dietary factors may alter the gut microbiota and intestinal barrier function, favoring the occurrence of metabolic endotoxemia and low grade inflammation, thereby contributing to the development of obesity and obesity-associated fatty liver disease. Therapeutic manipulations with prebiotics and probiotics to modulate the gut microbiota and maintain intestinal barrier integrity are potential agents for NAFLD management. This review summarizes the current knowledge regarding the complex interplay between the gut microbiota, intestinal barrier, and dietary factors in NAFLD pathogenesis. The concepts addressed in this review have important clinical implications, although more work needs to be done to understand how dietary factors affect the gut barrier and microbiota, and to comprehend how microbe-derived components may interfere with the host's metabolism contributing to NAFLD development.
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Affiliation(s)
- Irina A Kirpich
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville School of Medicine, 40202, Louisville, KY, USA; Department of Pharmacology and Toxicology, University of Louisville School of Medicine, 40202, Louisville, KY, USA.
| | - Luis S Marsano
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville School of Medicine, 40202, Louisville, KY, USA.
| | - Craig J McClain
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville School of Medicine, 40202, Louisville, KY, USA; Department of Pharmacology and Toxicology, University of Louisville School of Medicine, 40202, Louisville, KY, USA; Robley Rex Veterans Medical Center, 40202, Louisville, KY, USA.
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219
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Bashir M, Prietl B, Tauschmann M, Mautner SI, Kump PK, Treiber G, Wurm P, Gorkiewicz G, Högenauer C, Pieber TR. Effects of high doses of vitamin D3 on mucosa-associated gut microbiome vary between regions of the human gastrointestinal tract. Eur J Nutr 2015; 55:1479-89. [PMID: 26130323 PMCID: PMC4875045 DOI: 10.1007/s00394-015-0966-2] [Citation(s) in RCA: 151] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 06/16/2015] [Indexed: 12/12/2022]
Abstract
PURPOSE Vitamin D is well known for its effects on bone mineralisation but has also been attributed immunomodulatory properties. It positively influences human health, but in vivo data describing vitamin D effects on the human gut microbiome are missing. We aimed to investigate the effects of oral vitamin D3 supplementation on the human mucosa-associated and stool microbiome as well as CD8(+) T cells in healthy volunteers. METHODS This was an interventional, open-label, pilot study. Sixteen healthy volunteers (7 females, 9 males) were endoscopically examined to access a total of 7 sites. We sampled stomach, small bowel, colon, and stools before and after 8 weeks of vitamin D3 supplementation. Bacterial composition was assessed by pyrosequencing the 16S rRNA gene (V1-2), and CD8(+) T cell counts were determined by flow cytometry. RESULTS Vitamin D3 supplementation changed the gut microbiome in the upper GI tract (gastric corpus, antrum, and duodenum). We found a decreased relative abundance of Gammaproteobacteria including Pseudomonas spp. and Escherichia/Shigella spp. and increased bacterial richness. No major changes occurred in the terminal ileum, appendiceal orifice, ascending colon, and sigmoid colon or in stools, but the CD8(+) T cell fraction was significantly increased in the terminal ileum. CONCLUSION Vitamin D3 modulates the gut microbiome of the upper GI tract which might explain its positive influence on gastrointestinal diseases, such as inflammatory bowel disease or bacterial infections. The local effects of vitamin D demonstrate pronounced regional differences in the response of the GI microbiome to external factors, which should be considered in future studies investigating the human microbiome.
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Affiliation(s)
- Mina Bashir
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria
| | - Barbara Prietl
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria
| | - Martin Tauschmann
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria
| | - Selma I Mautner
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria
| | - Patrizia K Kump
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Gerlies Treiber
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria
| | - Philipp Wurm
- Institute of Pathology, Medical University of Graz, Graz, Austria
| | | | - Christoph Högenauer
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria.
| | - Thomas R Pieber
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria.
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220
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Abdul-Hai A, Abdallah A, Malnick SDH. Influence of gut bacteria on development and progression of non-alcoholic fatty liver disease. World J Hepatol 2015; 7:1679-1684. [PMID: 26140087 PMCID: PMC4483549 DOI: 10.4254/wjh.v7.i12.1679] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 03/20/2015] [Accepted: 04/20/2015] [Indexed: 02/06/2023] Open
Abstract
The intestine of the human contains a dynamic population of microbes that have a symbiotic relationship with the host. In addition, there is an effect of the intestinal microbiota on metabolism and digestion. Non-alcoholic fatty liver disease (NAFLD) is a common cause worldwide of hepatic pathology and is thought to be the hepatic manifestation of the metabolic syndrome. In this review we examine the effect of the human microbiome on the components and pathogenesis of the metabolic syndrome. We are now on the threshold of therapeutic interventions on the human microbiome in order to effect human disease including NAFLD.
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Fujimori S. What are the effects of proton pump inhibitors on the small intestine? World J Gastroenterol 2015; 21:6817-6819. [PMID: 26078557 PMCID: PMC4462721 DOI: 10.3748/wjg.v21.i22.6817] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 03/24/2015] [Accepted: 04/17/2015] [Indexed: 02/07/2023] Open
Abstract
Generally, proton-pump inhibitors (PPIs) have great benefit for patients with acid related disease with less frequently occurring side effects. According to a recent report, PPIs provoke dysbiosis of the small intestinal bacterial flora, exacerbating nonsteroidal anti-inflammatory drug-induced small intestinal injury. Several meta-analyses and systematic reviews have reported that patients treated with PPIs, as well as post-gastrectomy patients, have a higher frequency of small intestinal bacterial overgrowth (SIBO) compared to patients who lack the aforementioned conditions. Furthermore, there is insufficient evidence that these conditions induce Clostridium difficile infection. At this time, PPI-induced dysbiosis is considered a type of SIBO. It now seems likely that intestinal bacterial flora influence many diseases, such as inflammatory bowel disease, diabetes mellitus, obesity, non-alcoholic fatty liver disease, and autoimmune diseases. When attempting to control intestinal bacterial flora with probiotics, prebiotics, and fecal microbiota transplantation, etc., the influence of acid suppression therapy, especially PPIs, should not be overlooked.
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Bikel S, Valdez-Lara A, Cornejo-Granados F, Rico K, Canizales-Quinteros S, Soberón X, Del Pozo-Yauner L, Ochoa-Leyva A. Combining metagenomics, metatranscriptomics and viromics to explore novel microbial interactions: towards a systems-level understanding of human microbiome. Comput Struct Biotechnol J 2015; 13:390-401. [PMID: 26137199 PMCID: PMC4484546 DOI: 10.1016/j.csbj.2015.06.001] [Citation(s) in RCA: 132] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 06/01/2015] [Accepted: 06/04/2015] [Indexed: 02/07/2023] Open
Abstract
The advances in experimental methods and the development of high performance bioinformatic tools have substantially improved our understanding of microbial communities associated with human niches. Many studies have documented that changes in microbial abundance and composition of the human microbiome is associated with human health and diseased state. The majority of research on human microbiome is typically focused in the analysis of one level of biological information, i.e., metagenomics or metatranscriptomics. In this review, we describe some of the different experimental and bioinformatic strategies applied to analyze the 16S rRNA gene profiling and shotgun sequencing data of the human microbiome. We also discuss how some of the recent insights in the combination of metagenomics, metatranscriptomics and viromics can provide more detailed description on the interactions between microorganisms and viruses in oral and gut microbiomes. Recent studies on viromics have begun to gain importance due to the potential involvement of viruses in microbial dysbiosis. In addition, metatranscriptomic combined with metagenomic analysis have shown that a substantial fraction of microbial transcripts can be differentially regulated relative to their microbial genomic abundances. Thus, understanding the molecular interactions in the microbiome using the combination of metagenomics, metatranscriptomics and viromics is one of the main challenges towards a system level understanding of human microbiome.
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Affiliation(s)
- Shirley Bikel
- Unidad de Genómica de Poblaciones Aplicada la Salud, Facultad de Química, UNAM, Instituto Nacional de Medicina Genómica (INMEGEN), México, D.F. 14610, Mexico ; Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de Mexico, Avenida Universidad 2001, Cuernavaca C.P. 62210, Mexico
| | - Alejandra Valdez-Lara
- Unidad de Genómica de Poblaciones Aplicada la Salud, Facultad de Química, UNAM, Instituto Nacional de Medicina Genómica (INMEGEN), México, D.F. 14610, Mexico ; Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de Mexico, Avenida Universidad 2001, Cuernavaca C.P. 62210, Mexico
| | - Fernanda Cornejo-Granados
- Unidad de Genómica de Poblaciones Aplicada la Salud, Facultad de Química, UNAM, Instituto Nacional de Medicina Genómica (INMEGEN), México, D.F. 14610, Mexico ; Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de Mexico, Avenida Universidad 2001, Cuernavaca C.P. 62210, Mexico
| | - Karina Rico
- Unidad de Genómica de Poblaciones Aplicada la Salud, Facultad de Química, UNAM, Instituto Nacional de Medicina Genómica (INMEGEN), México, D.F. 14610, Mexico
| | - Samuel Canizales-Quinteros
- Unidad de Genómica de Poblaciones Aplicada la Salud, Facultad de Química, UNAM, Instituto Nacional de Medicina Genómica (INMEGEN), México, D.F. 14610, Mexico
| | - Xavier Soberón
- Instituto Nacional de Medicina Genómica (INMEGEN), México, D.F., Mexico
| | | | - Adrián Ochoa-Leyva
- Unidad de Genómica de Poblaciones Aplicada la Salud, Facultad de Química, UNAM, Instituto Nacional de Medicina Genómica (INMEGEN), México, D.F. 14610, Mexico ; Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de Mexico, Avenida Universidad 2001, Cuernavaca C.P. 62210, Mexico
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Gut Microbiota: Association with NAFLD and Metabolic Disturbances. BIOMED RESEARCH INTERNATIONAL 2015; 2015:979515. [PMID: 26090468 PMCID: PMC4452311 DOI: 10.1155/2015/979515] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 01/07/2015] [Indexed: 02/07/2023]
Abstract
Nonalcoholic fatty liver disease is the hepatic expression of metabolic syndrome, being frequently associated with obesity, insulin resistance, and dyslipidemia. Recent lines of evidence have demonstrated a role of gut microbiota in insulin resistance, obesity, and associated metabolic disturbances, raising the interest in its relationship with NAFLD pathogenesis. Therefore, intestinal microbiota has emerged as a potential factor involved in NAFLD, through different pathways, including its influence in energy storage, lipid and choline metabolism, ethanol production, immune balance, and inflammation. The main objective of this review is to address the pathogenic association of gut microbiota to NAFLD. This comprehension may allow the development of integrated strategies to modulate intestinal microbiota in order to treat NAFLD.
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Grąt M, Hołówko W, Wronka KM, Grąt K, Lewandowski Z, Kosińska I, Krasnodębski M, Wasilewicz M, Gałęcka M, Szachta P, Zborowska H, Patkowski W, Krawczyk M. The relevance of intestinal dysbiosis in liver transplant candidates. Transpl Infect Dis 2015; 17:174-84. [PMID: 25728703 DOI: 10.1111/tid.12352] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 06/18/2014] [Accepted: 12/11/2014] [Indexed: 12/11/2022]
Abstract
BACKGROUND The gut microbial ecosystem plays an important role in the pathogenesis of liver diseases. However, the association of microbial community structure with the severity of liver dysfunction is not completely understood. METHODS Fecal microflora was assessed in 40 patients with liver cirrhosis listed for primary liver transplantation (LT). Independent associations between fecal microbial counts and serum bilirubin, serum creatinine, international normalized ratio (INR), and the Model for End-stage Liver Disease (MELD) score were established in multiple linear regression models. RESULTS Bifidobacterium (standardized regression coefficient [sβ] = -0.549; P < 0.001), Enterococcus (sβ = 0.369; P = 0.004), and yeast (sβ = 0.315; P = 0.018) numbers were independently associated with serum bilirubin, while Escherichia coli counts (sβ = 0.318; P = 0.046) correlated with INR, and Bifidobacterium counts (sβ = 0.410; P = 0.009) with serum creatinine. Only Bifidobacterium (sβ = -0.468; P = 0.003) and Enterococcus (sβ = 0.331; P = 0.029) counts were independent predictors of the MELD score. Bifidobacterium/Enterococcus ratio, proposed as a measure of pre-LT gut dysbiosis, was significantly related to the MELD score following the adjustment for the absolute Bifidobacterium (sβ = -0.333; P = 0.029) and Enterococcus (sβ = -0.966; P = 0.003) numbers. This pre-transplant dysbiosis ratio (PTDR) was significantly correlated with Enterococcus (R = -0.897; P < 0.001) but not with Bifidobacterium (R = 0.098; P = 0.546) counts. Among the other components of gut microflora, only hydrogen peroxide (H2 O2 )-producing Lactobacillus strains significantly influenced Enterococcus counts (sβ = 0.349; P = 0.028) and PTDR (sβ = -0.318; P = 0.046). CONCLUSION While the abundance of both Bifidobacterium and Enterococcus is related to liver dysfunction, the size of the Enterococcus population seems to be the most important determinant of pre-LT gut dysbiosis in cirrhotic patients. The H2 O2 -producing Lactobacillus strains potentially ameliorate this dysbiotic state.
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Affiliation(s)
- M Grąt
- Department of General, Transplant, and Liver Surgery, Medical University of Warsaw, Warsaw, Poland
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225
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Zhu L, Baker RD, Baker SS. Gut microbiome and nonalcoholic fatty liver diseases. Pediatr Res 2015; 77:245-51. [PMID: 25310763 DOI: 10.1038/pr.2014.157] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2014] [Accepted: 08/22/2014] [Indexed: 02/07/2023]
Abstract
We review recent findings and hypotheses on the roles of gut microbiome in the pathogenesis of nonalcoholic fatty liver diseases (NAFLD). Microbial metabolites and cell components contribute to the development of hepatic steatosis and inflammation, key components of nonalcoholic steatohepatitis (NASH), the severe form of NAFLD. Altered gut microbiome can independently cause obesity, the most important risk factor for NAFLD. This capability is attributed to short-chain fatty acids (SCFAs), major gut microbial fermentation products. SCFAs account for a large portion of caloric intake of the host, and they enhance intestinal absorption by activating GLP-2 signaling. However, elevated SCFAs may be an adaptive measure to suppress colitis, which could be a higher priority than imbalanced calorie intake. The microbiome of NASH patients features an elevated capacity for alcohol production. The pathomechanisms for alcoholic steatohepatitis may apply to NASH. NAFLD/NASH is associated with elevated Gram-negative microbiome and endotoxemia. However, many NASH patients exhibited normal serum endotoxin indicating that endotoxemia is not required for the pathogenesis of NASH. These observations suggest that microbial intervention may benefit NAFLD/NASH patients. However, very limited effects were observed using traditional probiotic species. Novel probiotic therapy based on NAFLD/NASH specific microbial composition represents a promising future direction.
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Affiliation(s)
- Lixin Zhu
- Department of Pediatrics, Women and Children's Hospital of Buffalo, Digestive Diseases and Nutrition Center, The State University of New York at Buffalo, Buffalo, New York
| | - Robert D Baker
- Department of Pediatrics, Women and Children's Hospital of Buffalo, Digestive Diseases and Nutrition Center, The State University of New York at Buffalo, Buffalo, New York
| | - Susan S Baker
- Department of Pediatrics, Women and Children's Hospital of Buffalo, Digestive Diseases and Nutrition Center, The State University of New York at Buffalo, Buffalo, New York
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226
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The gut microbiota of Colombians differs from that of Americans, Europeans and Asians. BMC Microbiol 2014; 14:311. [PMID: 25495462 PMCID: PMC4275940 DOI: 10.1186/s12866-014-0311-6] [Citation(s) in RCA: 150] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 11/25/2014] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND The composition of the gut microbiota has recently been associated with health and disease, particularly with obesity. Some studies suggested a higher proportion of Firmicutes and a lower proportion of Bacteroidetes in obese compared to lean people; others found discordant patterns. Most studies, however, focused on Americans or Europeans, giving a limited picture of the gut microbiome. To determine the generality of previous observations and expand our knowledge of the human gut microbiota, it is important to replicate studies in overlooked populations. Thus, we describe here, for the first time, the gut microbiota of Colombian adults via the pyrosequencing of the 16S ribosomal DNA (rDNA), comparing it with results obtained in Americans, Europeans, Japanese and South Koreans, and testing the generality of previous observations concerning changes in Firmicutes and Bacteroidetes with increasing body mass index (BMI). RESULTS We found that the composition of the gut microbiota of Colombians was significantly different from that of Americans, Europeans and Asians. The geographic origin of the population explained more variance in the composition of this bacterial community than BMI or gender. Concerning changes in Firmicutes and Bacteroidetes with obesity, in Colombians we found a tendency in Firmicutes to diminish with increasing BMI, whereas no change was observed in Bacteroidetes. A similar result was found in Americans. A more detailed inspection of the Colombian dataset revealed that five fiber-degrading bacteria, including Akkermansia, Dialister, Oscillospira, Ruminococcaceae and Clostridiales, became less abundant in obese subjects. CONCLUSION We contributed data from unstudied Colombians that showed that the geographic origin of the studied population had a greater impact on the composition of the gut microbiota than BMI or gender. Any strategy aiming to modulate or control obesity via manipulation of this bacterial community should consider this effect.
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227
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Paolella G, Mandato C, Pierri L, Poeta M, Di Stasi M, Vajro P. Gut-liver axis and probiotics: Their role in non-alcoholic fatty liver disease. World J Gastroenterol 2014; 20:15518-15531. [PMID: 25400436 PMCID: PMC4229517 DOI: 10.3748/wjg.v20.i42.15518] [Citation(s) in RCA: 126] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Revised: 04/29/2014] [Accepted: 07/16/2014] [Indexed: 02/06/2023] Open
Abstract
The incidence of obesity and its related conditions, including non-alcoholic fatty liver disease (NAFLD), has dramatically increased in all age groups worldwide. Given the health consequences of these conditions, and the subsequent economic burden on healthcare systems, their prevention and treatment have become major priorities. Because standard dietary and lifestyle changes and pathogenically-oriented therapies (e.g., antioxidants, oral hypoglycemic agents, and lipid-lowering agents) often fail due to poor compliance and/or lack of efficacy, novel approaches directed toward other pathomechanisms are needed. Here we present several lines of evidence indicating that, by increasing energy extraction in some dysbiosis conditions or small intestinal bacterial overgrowth, specific gut microbiota and/or a “low bacterial richness” may play a role in obesity, metabolic syndrome, and fatty liver. Under conditions involving a damaged intestinal barrier (“leaky gut”), the gut-liver axis may enhance the natural interactions between intestinal bacteria/bacterial products and hepatic receptors (e.g., toll-like receptors), thus promoting the following cascade of events: oxidative stress, insulin-resistance, hepatic inflammation, and fibrosis. We also discuss the possible modulation of gut microbiota by probiotics, as attempted in NAFLD animal model studies and in several pilot pediatric and adult human studies. Globally, this approach appears to be a promising and innovative add-on therapeutic tool for NAFLD in the context of multi-target therapy.
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228
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Joice R, Yasuda K, Shafquat A, Morgan XC, Huttenhower C. Determining microbial products and identifying molecular targets in the human microbiome. Cell Metab 2014; 20:731-741. [PMID: 25440055 PMCID: PMC4254638 DOI: 10.1016/j.cmet.2014.10.003] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Human-associated microbes are the source of many bioactive microbial products (proteins and metabolites) that play key functions both in human host pathways and in microbe-microbe interactions. Culture-independent studies now provide an accelerated means of exploring novel bioactives in the human microbiome; however, intriguingly, a substantial fraction of the microbial metagenome cannot be mapped to annotated genes or isolate genomes and is thus of unknown function. Meta'omic approaches, including metagenomic sequencing, metatranscriptomics, metabolomics, and integration of multiple assay types, represent an opportunity to efficiently explore this large pool of potential therapeutics. In combination with appropriate follow-up validation, high-throughput culture-independent assays can be combined with computational approaches to identify and characterize novel and biologically interesting microbial products. Here we briefly review the state of microbial product identification and characterization and discuss possible next steps to catalog and leverage the large uncharted fraction of the microbial metagenome.
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Affiliation(s)
- Regina Joice
- Department of Biostatistics, Harvard School of Public Health, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Koji Yasuda
- Department of Biostatistics, Harvard School of Public Health, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Afrah Shafquat
- Department of Biostatistics, Harvard School of Public Health, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Xochitl C Morgan
- Department of Biostatistics, Harvard School of Public Health, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Curtis Huttenhower
- Department of Biostatistics, Harvard School of Public Health, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
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229
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Pallayova M, Taheri S. Non-alcoholic fatty liver disease in obese adults: clinical aspects and current management strategies. Clin Obes 2014; 4:243-53. [PMID: 25825857 DOI: 10.1111/cob.12068] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 05/15/2014] [Accepted: 05/28/2014] [Indexed: 12/18/2022]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder whose prevalence is strongly linked to the current epidemic of obesity in many western countries. The prevalence of NAFLD is two to four times higher in populations with pre-existing metabolic comorbidities than in the general population. The diagnosis of primary NAFLD involves establishing the presence of hepatic steatosis or steatohepatitis by imaging or histology, along with establishing the non-alcoholic nature of the disease process and excluding competing aetiologies for hepatic steatosis. Among the indirect serum biomarkers, the NAFLD fibrosis score can help to identify patients with NAFLD and with higher likelihood of having fibrosis or cirrhosis. A liver biopsy should be considered in NAFLD patients at increased risk for steatohepatitis/advanced fibrosis and in cases where a liver biopsy is necessary to exclude co-existing chronic liver diseases and other aetiologies for hepatic steatosis. The treatment and management recommendations for obesity-associated NAFLD are aimed towards weight reduction. The currently available interventions employed to promote weight loss and improve the metabolic responses in NAFLD include lifestyle modification, pharmacotherapy and bariatric surgery.
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Affiliation(s)
- M Pallayova
- Faculty of Medicine, PJ Safarik University, Kosice, Slovak Republic
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230
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McFarland LV. Use of probiotics to correct dysbiosis of normal microbiota following disease or disruptive events: a systematic review. BMJ Open 2014; 4:e005047. [PMID: 25157183 PMCID: PMC4156804 DOI: 10.1136/bmjopen-2014-005047] [Citation(s) in RCA: 126] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 07/30/2014] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVE To assess the evidence for the claim probiotics can correct dysbiosis of the normal microbiota resulting from disease or disruptive events. SETTING Systematic review of published clinical trials of patients receiving a probiotic intervention for the prevention or treatment of various diseases. DATA SOURCES Sources searched (1985-2013): PubMed, EMBASE, Cochrane Database of Systematic Reviews, CINAHL, AMED and ISI Web of Science. Three on-line clinical trial registries were searched: Cochrane Central Register of Controlled trials, MetaRegister of Controlled Trials and National Institutes of Health. REVIEW METHODS Included studies were randomised clinical trials of probiotic interventions having microbiological assays. Studies were evaluated following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for specific probiotic strains. A standard data extraction form was used to collect the raw data. OUTCOME MEASURES The primary outcome is the degree of microbiota correction by specific probiotic strains. Secondary outcome was the association between the degree of dysbiosis correction and clinical efficacy. RESULTS The review of the literature found three distinct study designs: model A (restoration) assayed patients enrolled with a healthy, undisturbed microbiota and then assayed postdisruptive event and probiotic therapy; model B (alteration) assayed patients with pre-existing disrupted microbiota and then postprobiotic therapy; model C (no dysbiosis) assayed volunteers with no disruptive event prebiotic and postprobiotic. From a total of 63 trials, 83% of the probiotic products using model A restored the microbiota, 56% using model B improved the microbiota and only 21% using model C had any effect on microbiota. Clinical efficacy was more commonly associated with strains capable of restoration of the normal microbiota. CONCLUSIONS The ability to assess the degree of dysbiosis improvement is dependent on the enrolled population and the timing of microbiological assays. The functional claim for correcting dysbiosis is poorly supported for most probiotic strains and requires further research. TRIAL REGISTRATION NUMBER PROSPERO (CRD42014007224).
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Affiliation(s)
- Lynne V McFarland
- Department of Medicinal Chemistry, School of Pharmacy, University of Washington, Seattle, Washington, USA
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231
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Meta-omic platforms to assist in the understanding of NAFLD gut microbiota alterations: tools and applications. Int J Mol Sci 2014; 15:684-711. [PMID: 24402126 PMCID: PMC3907832 DOI: 10.3390/ijms15010684] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2013] [Revised: 12/29/2013] [Accepted: 01/02/2014] [Indexed: 12/13/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide as a result of the increasing prevalence of obesity, starting from early life stages. It is characterized by a spectrum of liver diseases ranging from simple fatty liver (NAFL) to steatohepatitis (NASH), with a possible progression to fibrosis, thus increasing liver-related morbidity and mortality. NAFLD development is driven by the co-action of several risk factors, including obesity and metabolic syndrome, which may be both genetically induced and diet-related. Recently, particular attention has been paid to the gut-liver axis, which may play a physio-pathological role in the onset and progression of the disease. The gut microbiota is intended to act as a bioreactor that can guarantee autonomous metabolic and immunological functions and that can drive functional strategies within the environment of the body in response to external stimuli. The complexity of the gut microbiota suggests that it behaves as an organ. Therefore, the concept of the gut-liver axis must be complemented with the gut-microbiota-liver network due to the high intricacy of the microbiota components and metabolic activities; these activities form the active diet-driven power plant of the host. Such complexity can only be revealed using systems biology, which can integrate clinical phenomics and gut microbiota data.
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232
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Quigley EM, Monsour HP. The gut microbiota and the liver: implications for clinical practice. Expert Rev Gastroenterol Hepatol 2013; 7:723-32. [PMID: 24134195 DOI: 10.1586/17474124.2013.848167] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
While a central role for the microbiota in the precipitation of infectious and non-infectious complications of liver disease has been long established, evidence for a more fundamental role in the etiology of several liver diseases continues to accumulate. However, though progress is rapidly occurring in this area, the definitive delineation of the precise relevance of changes in the microbiota to various forms and stages of liver disease is still far from complete. While high quality clinical evidence supports the use of antibiotic therapy, in the management of hepatic encephalopathy, spontaneous bacterial peritonitis and other infectious complications, how these interventions impact on the microbiota and microbiota-host interactions has not been clearly defined. Although probiotics and even, perhaps, fecal transplantation hold promise in the management of liver disease, and the potential impact of probiotics is supported by a considerable amount of laboratory data, high-quality clinical evidence is scanty.
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Affiliation(s)
- Eamonn M Quigley
- Gastroenterology and Hepatology, Houston Methodist Hospital and Weill Cornell Medical College, Houston, Texas, USA
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233
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Neef A, Sanz Y. Future for probiotic science in functional food and dietary supplement development. Curr Opin Clin Nutr Metab Care 2013; 16:679-87. [PMID: 24071779 DOI: 10.1097/mco.0b013e328365c258] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
PURPOSE OF REVIEW The purpose of this study is to provide an update of probiotic science evolving from classical approaches to the development of next-generation probiotics, parallel to advances in the understanding of the complexity of the gut microbiome and its role in human health. RECENT FINDINGS The probiotic concept is based on the notion that the gut ecosystem contributes to human physiology and, consequently, its modulation may help to maintain health and reduce disease risk. The understanding of the complexity of the gut microbiota and the specific components associated with progression from health to disease is rapidly increasing, thanks to the use of high-throughput and next-generation sequencing techniques in progressively better controlled epidemiological studies. Evidence on microbiome-mediated effects by intervention with classical probiotics on humans is, however, limited. The new information is helping to set a rationale for selection of a next generation of probiotics. Candidates include Clostridia clusters IV, XIVa and XVIII, Faecalibacterium prausnitzii, Akkermansia muciniphila and Bacteroides uniformis, the effects of which have been evaluated in preclinical trials with promising results for inflammatory and diet-related disorders. Yet, the extent to which new probiotic formulations consisting of nonconventional indigenous gut bacteria will be effective on humans at a population level or in personalized nutrition strategies remains to be explored. SUMMARY Understanding the role that indigenous intestinal bacteria and their ecological interactions play in human health and disease based on epidemiological, intervention and mechanistic studies will provide a robust rationale for selection of probiotic strains and facilitate the optimization of integrated dietary strategies to efficiently modulate the human gut microbiome, leading to improvements in nutrition and clinical practice.
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Affiliation(s)
- Alexander Neef
- Microbial Ecology, Nutrition & Health Research Group, Institute of Agrochemistry and Food Technology, National Research Council (IATA-CSIC), Valencia, Spain
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