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Varma R, Chakraborty S, Burton DD, Bailey KR, Bharucha AE. Small intestinal bacterial overgrowth in diabetic gastroenteropathy. Neurogastroenterol Motil 2024; 36:e14798. [PMID: 38651669 DOI: 10.1111/nmo.14798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 03/06/2024] [Accepted: 04/03/2024] [Indexed: 04/25/2024]
Abstract
BACKGROUND Although diabetic gastroenteropathy (DGE) is associated with small intestinal bacterial overgrowth (SIBO), most studies have evaluated SIBO with a hydrogen breath test, which may be affected by altered transit in DGE. The risk factors for the consequences of SIBO in DGE are poorly understood. We aimed to evaluate the prevalence of, risk factors for, and gastrointestinal symptoms associated with SIBO in patients with DGE. METHODS In 75 patients with DGE and dyspepsia, we tested for SIBO (≥105 colony forming units /mL of aerobic and/or anaerobic bacteria in a duodenal aspirate) and assessed gastric emptying (GE) of solids, symptoms during a GE study and during an enteral lipid challenge (300 kcal/2 h), and daily symptoms with a Gastroparesis Cardinal Symptom Index diary for 2 weeks. Symptoms and GE were compared in patients with versus without SIBO. KEY RESULTS Of 75 patients, 34 (45%) had SIBO, which was not associated with the use of proton pump inhibitors, daily symptoms, GE, or symptoms during a GE study. During enteral lipid challenge, severe nausea (p = 0.006), fullness (p = 0.02) and bloating (p = 0.009) were each associated with SIBO. Twenty patients (59%) with versus 13 (32%) without SIBO had at least one severe symptom during the lipid challenge (p = 0.006). CONCLUSIONS & INFERENCES Among patients with DGE 45% had SIBO, which was associated with symptoms during enteral lipid challenge but not with delayed GE, symptoms during a GE study, or daily symptoms. Perhaps bacterial products and even fatty acids are recognized by and activate mast cells that drive the increased lipid sensitivity in SIBO.
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Affiliation(s)
- Revati Varma
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Duane D Burton
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
| | - Kent R Bailey
- Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota, USA
| | - Adil E Bharucha
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
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2
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Alcedo González J, Estremera-Arévalo F, Cobián Malaver J, Santos Vicente J, Alcalá-González LG, Naves J, Barba Orozco E, Barber Caselles C, Serrano-Falcón B, Accarino Garaventa A, Alonso-Cotoner C, Serra Pueyo J. Common questions and rationale answers about the intestinal bacterial overgrowth syndrome (SIBO). GASTROENTEROLOGIA Y HEPATOLOGIA 2024:502216. [PMID: 38852778 DOI: 10.1016/j.gastrohep.2024.502216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 05/15/2024] [Accepted: 05/24/2024] [Indexed: 06/11/2024]
Affiliation(s)
- Javier Alcedo González
- Servicio de Aparato Digestivo, Hospital Universitario Miguel Servet, Instituto de Investigación Sanitaria (IIS) Aragón, Zaragoza, España.
| | - Fermín Estremera-Arévalo
- Servicio de Aparato Digestivo, Hospital Universitario de Navarra, Navarrabiomed, Universidad Pública de Navarra - IdiSNA, Navarra, España
| | | | - Javier Santos Vicente
- Laboratorio de Neuro-Inmuno-Gastroenterología, Unidad de Investigación de Aparato Digestivo, Institut de Recerca (VHIR), Servicio de Aparato Digestivo, Hospital Universitario Vall d'Hebron, Barcelona, España; Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (Ciberehd), Instituto de Salud Carlos III, Madrid, España
| | | | - Juan Naves
- Servicio de Aparato Digestivo, Hospital del Mar, Barcelona, España
| | - Elizabeth Barba Orozco
- Unidad de Neurogastroenterología y Motilidad, Hospital Clínic de Barcelona, Barcelona, España; Departamento de Gastroenterología, Universidad de Barcelona, Barcelona, España
| | | | - Blanca Serrano-Falcón
- Servicio de Aparato Digestivo, Hospital Universitario Virgen de las Nieves, Granada, España
| | | | - Carmen Alonso-Cotoner
- Laboratorio de Neuro-Inmuno-Gastroenterología, Unidad de Investigación de Aparato Digestivo, Institut de Recerca (VHIR), Servicio de Aparato Digestivo, Hospital Universitario Vall d'Hebron, Barcelona, España; Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (Ciberehd), Instituto de Salud Carlos III, Madrid, España; Facultad de Medicina, Universidad Autónoma de Barcelona, Barcelona, España
| | - Jordi Serra Pueyo
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (Ciberehd), Instituto de Salud Carlos III, Madrid, España; Área de Aparato Digestivo, Hospital Universitario Vall d'Hebron, Barcelona, España
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3
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Guo H, Chen Y, Dong W, Lu S, Du Y, Duan L. Fecal Coprococcus, hidden behind abdominal symptoms in patients with small intestinal bacterial overgrowth. J Transl Med 2024; 22:496. [PMID: 38796441 PMCID: PMC11128122 DOI: 10.1186/s12967-024-05316-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Accepted: 05/20/2024] [Indexed: 05/28/2024] Open
Abstract
BACKGROUND Small intestinal bacterial overgrowth (SIBO) is the presence of an abnormally excessive amount of bacterial colonization in the small bowel. Hydrogen and methane breath test has been widely applied as a non-invasive method for SIBO. However, the positive breath test representative of bacterial overgrowth could also be detected in asymptomatic individuals. METHODS To explore the relationship between clinical symptoms and gut dysbiosis, and find potential fecal biomarkers for SIBO, we compared the microbial profiles between SIBO subjects with positive breath test but without abdominal symptoms (PBT) and healthy controls (HC) using 16S rRNA amplicon sequencing. RESULTS Fecal samples were collected from 63 SIBO who complained of diarrhea, distension, constipation, or abdominal pain, 36 PBT, and 55 HC. For alpha diversity, the Shannon index of community diversity on the genus level showed a tendency for a slight increase in SIBO, while the Shannon index on the predicted function was significantly decreased in SIBO. On the genus level, significantly decreased Bacteroides, increased Coprococcus_2, and unique Butyrivibrio were observed in SIBO. There was a significant positive correlation between saccharolytic Coprococcus_2 and the severity of abdominal symptoms. Differently, the unique Veillonella in the PBT group was related to amino acid fermentation. Interestingly, the co-occurrence network density of PBT was larger than SIBO, which indicates a complicated interaction of genera. Coprococcus_2 showed one of the largest betweenness centrality in both SIBO and PBT microbiota networks. Pathway analysis based on the Kyoto Encyclopedia of Genes and Genome (KEGG) database reflected that one carbon pool by folate and multiple amino acid metabolism were significantly down in SIBO. CONCLUSIONS This study provides valuable insights into the fecal microbiota composition and predicted metabolic functional changes in patients with SIBO. Butyrivibrio and Coprococcus_2, both renowned for their role in carbohydrate fermenters and gas production, contributed significantly to the symptoms of the patients. Coprococcus's abundance hints at its use as a SIBO marker. Asymptomatic PBT individuals show a different microbiome, rich in Veillonella. PBT's complex microbial interactions might stabilize the intestinal ecosystem, but further study is needed due to the core microbiota similarities with SIBO. Predicted folate and amino acid metabolism reductions in SIBO merit additional validation.
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Affiliation(s)
- Huaizhu Guo
- Department of Gastroenterology, Peking University Third Hospital, Beijing, China
| | - Yuzhu Chen
- Department of Gastroenterology, Peking University Third Hospital, Beijing, China
| | - Wenxin Dong
- Department of Pediatrics, Peking University Third Hospital, Beijing, China
| | - Siqi Lu
- Department of Gastroenterology, Peking University Third Hospital, Beijing, China
| | - Yanlin Du
- Department of Gastroenterology, Peking University Third Hospital, Beijing, China
| | - Liping Duan
- Department of Gastroenterology, Peking University Third Hospital, Beijing, China.
- International Institute of Population Health, Peking University Health Science Center, Beijing, China.
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Kuehnast T, Kumpitsch C, Mohammadzadeh R, Weichhart T, Moissl-Eichinger C, Heine H. Exploring the human archaeome: its relevance for health and disease, and its complex interplay with the human immune system. FEBS J 2024. [PMID: 38555566 DOI: 10.1111/febs.17123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 02/23/2024] [Accepted: 03/11/2024] [Indexed: 04/02/2024]
Abstract
This Review aims to coalesce existing knowledge on the human archaeome, a less-studied yet critical non-bacterial component of the human microbiome, with a focus on its interaction with the immune system. Despite a largely bacteria-centric focus in microbiome research, archaea present unique challenges and opportunities for understanding human health. We examine the archaeal distribution across different human body sites, such as the lower gastrointestinal tract (LGT), upper aerodigestive tract (UAT), urogenital tract (UGT), and skin. Variability in archaeal composition exists between sites; methanogens dominate the LGT, while Nitrososphaeria are prevalent on the skin and UAT. Archaea have yet to be classified as pathogens but show associations with conditions such as refractory sinusitis and vaginosis. In the LGT, methanogenic archaea play critical metabolic roles by converting bacterial end-products into methane, correlating with various health conditions, including obesity and certain cancers. Finally, this work looks at the complex interactions between archaea and the human immune system at the molecular level. Recent research has illuminated the roles of specific archaeal molecules, such as RNA and glycerolipids, in stimulating immune responses via innate immune receptors like Toll-like receptor 8 (TLR8) and 'C-type lectin domain family 4 member E' (CLEC4E; also known as MINCLE). Additionally, metabolic by-products of archaea, specifically methane, have demonstrated immunomodulatory effects through anti-inflammatory and anti-oxidative pathways. Despite these advancements, the mechanistic underpinnings of how archaea influence immune activity remain a fertile area for further investigation.
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Affiliation(s)
- Torben Kuehnast
- D&R Institute for Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Austria
| | - Christina Kumpitsch
- D&R Institute for Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Austria
| | - Rokhsareh Mohammadzadeh
- D&R Institute for Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Austria
| | - Thomas Weichhart
- Institute of Medical Genetics, Medical University of Vienna, Austria
| | - Christine Moissl-Eichinger
- D&R Institute for Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Austria
- BioTechMed Graz, Austria
| | - Holger Heine
- Research Center Borstel - Leibniz Lung Center, Division of Innate Immunity, Airway Research Center North (ARCN), German Center for Lung Research (DZL), Borstel, Germany
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Orgler E, Baumgartner M, Duller S, Kumptisch C, Hausmann B, Moser D, Khare V, Lang M, Köcher T, Frick A, Muttenthaler M, Makristathis A, Moissl-Eichinger C, Gasche C. Archaea influence composition of endoscopically visible ileocolonic biofilms. Gut Microbes 2024; 16:2359500. [PMID: 38825783 DOI: 10.1080/19490976.2024.2359500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 05/21/2024] [Indexed: 06/04/2024] Open
Abstract
The gut microbiota has been implicated as a driver of irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). Recently we described, mucosal biofilms, signifying alterations in microbiota composition and bile acid (BA) metabolism in IBS and ulcerative colitis (UC). Luminal oxygen concentration is a key factor in the gastrointestinal (GI) ecosystem and might be increased in IBS and UC. Here we analyzed the role of archaea as a marker for hypoxia in mucosal biofilms and GI homeostasis. The effects of archaea on microbiome composition and metabolites were analyzed via amplicon sequencing and untargeted metabolomics in 154 stool samples of IBS-, UC-patients and controls. Mucosal biofilms were collected in a subset of patients and examined for their bacterial, fungal and archaeal composition. Absence of archaea, specifically Methanobrevibacter, correlated with disrupted GI homeostasis including decreased microbial diversity, overgrowth of facultative anaerobes and conjugated secondary BA. IBS-D/-M was associated with absence of archaea. Presence of Methanobrevibacter correlated with Oscillospiraceae and epithelial short chain fatty acid metabolism and decreased levels of Ruminococcus gnavus. Absence of fecal Methanobrevibacter may indicate a less hypoxic GI environment, reduced fatty acid oxidation, overgrowth of facultative anaerobes and disrupted BA deconjugation. Archaea and Ruminococcus gnavus could distinguish distinct subtypes of mucosal biofilms. Further research on the connection between archaea, mucosal biofilms and small intestinal bacterial overgrowth should be performed.
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Affiliation(s)
- Elisabeth Orgler
- Division of Gastroenterology and Hepatology, Department of Internal Medicine 3, Medical University of Vienna, Vienna, Austria
- Diagnostic and Research Center for Molecular BioMedicine, Diagnostic and Research Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Graz, Austria
- Department of Medicine II, University Hospital, Munich, Germany
| | - Maximilian Baumgartner
- Division of Gastroenterology and Hepatology, Department of Internal Medicine 3, Medical University of Vienna, Vienna, Austria
| | - Stefanie Duller
- Diagnostic and Research Center for Molecular BioMedicine, Diagnostic and Research Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Graz, Austria
| | - Christina Kumptisch
- Diagnostic and Research Center for Molecular BioMedicine, Diagnostic and Research Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Graz, Austria
| | - Bela Hausmann
- Centre for Microbiology and Environmental Systems Science, Joint Microbiome Facility of the Medical University of Vienna and the University of Vienna, Vienna, Austria
- Division of Microbiology, Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Doris Moser
- Department of Cranio-Maxillofacial and Oral Surgery, Medical University of Vienna, Vienna, Austria
| | - Vineeta Khare
- Division of Gastroenterology and Hepatology, Department of Internal Medicine 3, Medical University of Vienna, Vienna, Austria
| | - Michaela Lang
- Division of Gastroenterology and Hepatology, Department of Internal Medicine 3, Medical University of Vienna, Vienna, Austria
- Centre for Microbiology and Environmental Systems Science, Joint Microbiome Facility of the Medical University of Vienna and the University of Vienna, Vienna, Austria
| | - Thomas Köcher
- Metabolomics Service and Research Facility, Vienna Biocenter Core Facilities, Vienna, Austria
| | - Adrian Frick
- Division of Gastroenterology and Hepatology, Department of Internal Medicine 3, Medical University of Vienna, Vienna, Austria
| | - Markus Muttenthaler
- Faculty of Chemistry, Institute of Biological Chemistry, University of Vienna, Vienna, Austria
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Athanasios Makristathis
- Centre for Microbiology and Environmental Systems Science, Joint Microbiome Facility of the Medical University of Vienna and the University of Vienna, Vienna, Austria
- Division of Microbiology, Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Christine Moissl-Eichinger
- Diagnostic and Research Center for Molecular BioMedicine, Diagnostic and Research Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Graz, Austria
| | - Christoph Gasche
- Division of Gastroenterology and Hepatology, Department of Internal Medicine 3, Medical University of Vienna, Vienna, Austria
- Loha for Life, Center for Gastroenterology and Iron Deficiency, Vienna, Austria
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Efremova I, Maslennikov R, Poluektova E, Vasilieva E, Zharikov Y, Suslov A, Letyagina Y, Kozlov E, Levshina A, Ivashkin V. Epidemiology of small intestinal bacterial overgrowth. World J Gastroenterol 2023; 29:3400-3421. [PMID: 37389240 PMCID: PMC10303511 DOI: 10.3748/wjg.v29.i22.3400] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 03/31/2023] [Accepted: 05/11/2023] [Indexed: 06/06/2023] Open
Abstract
Small intestinal bacterial overgrowth (SIBO) is defined as an increase in the bacterial content of the small intestine above normal values. The presence of SIBO is detected in 33.8% of patients with gastroenterological complaints who underwent a breath test, and is significantly associated with smoking, bloating, abdominal pain, and anemia. Proton pump inhibitor therapy is a significant risk factor for SIBO. The risk of SIBO increases with age and does not depend on gender or race. SIBO complicates the course of a number of diseases and may be of pathogenetic significance in the development of their symptoms. SIBO is significantly associated with functional dyspepsia, irritable bowel syndrome, functional abdominal bloating, functional constipation, functional diarrhea, short bowel syndrome, chronic intestinal pseudo-obstruction, lactase deficiency, diverticular and celiac diseases, ulcerative colitis, Crohn’s disease, cirrhosis, metabolic-associated fatty liver disease (MAFLD), primary biliary cholangitis, gastroparesis, pancreatitis, cystic fibrosis, gallstone disease, diabetes, hypothyroidism, hyperlipidemia, acromegaly, multiple sclerosis, autism, Parkinson’s disease, systemic sclerosis, spondylarthropathy, fibromyalgia, asthma, heart failure, and other diseases. The development of SIBO is often associated with a slowdown in orocecal transit time that decreases the normal clearance of bacteria from the small intestine. The slowdown of this transit may be due to motor dysfunction of the intestine in diseases of the gut, autonomic diabetic polyneuropathy, and portal hypertension, or a decrease in the motor-stimulating influence of thyroid hormones. In a number of diseases, including cirrhosis, MAFLD, diabetes, and pancreatitis, an association was found between disease severity and the presence of SIBO. Further work on the effect of SIBO eradication on the condition and prognosis of patients with various diseases is required.
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Affiliation(s)
- Irina Efremova
- Department of Internal Medicine, Gastroenterology and Hepatology, Sechenov University, Moscow 119435, Russia
| | - Roman Maslennikov
- Department of Internal Medicine, Gastroenterology and Hepatology, Sechenov University, Moscow 119435, Russia
- The Scientific Community for Human Microbiome Research, Moscow 119435, Russia
| | - Elena Poluektova
- Department of Internal Medicine, Gastroenterology and Hepatology, Sechenov University, Moscow 119435, Russia
- The Scientific Community for Human Microbiome Research, Moscow 119435, Russia
| | - Ekaterina Vasilieva
- Department of Internal Medicine, Gastroenterology and Hepatology, Sechenov University, Moscow 119435, Russia
| | - Yury Zharikov
- Department of Human Anatomy and Histology, Sechenov University, Moscow 125009, Russia
| | - Andrey Suslov
- Department of Human Anatomy and Histology, Sechenov University, Moscow 125009, Russia
| | - Yana Letyagina
- N.V. Sklifosovsky Institute of Clinical Medicine, Sechenov University, Moscow 119991, Russia
| | - Evgenii Kozlov
- Department of Clinical Immunology and Allergy, Sechenov University, Moscow 119991, Russia
| | - Anna Levshina
- Department of Internal Medicine, Gastroenterology and Hepatology, Sechenov University, Moscow 119435, Russia
- Department of Clinical Immunology and Allergy, Sechenov University, Moscow 119991, Russia
| | - Vladimir Ivashkin
- Department of Internal Medicine, Gastroenterology and Hepatology, Sechenov University, Moscow 119435, Russia
- The Scientific Community for Human Microbiome Research, Moscow 119435, Russia
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Tansel A, Levinthal DJ. Understanding Our Tests: Hydrogen-Methane Breath Testing to Diagnose Small Intestinal Bacterial Overgrowth. Clin Transl Gastroenterol 2023; 14:e00567. [PMID: 36744854 PMCID: PMC10132719 DOI: 10.14309/ctg.0000000000000567] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 01/26/2023] [Indexed: 02/07/2023] Open
Abstract
There is increasing appreciation that small intestinal bacterial overgrowth (SIBO) drives many common gastrointestinal symptoms, including diarrhea, bloating, and abdominal pain. Breath testing via measurement of exhaled hydrogen and methane gases following ingestion of a readily metabolized carbohydrate has become an important noninvasive testing paradigm to help diagnose SIBO. However, because of a number of physiological and technical considerations, how and when to use breath testing in the diagnosis of SIBO remains a nuanced clinical decision. This narrative review provides a comprehensive overview of breath testing paradigms including the indications for testing, how to administer the test, and how patient factors influence breath testing results. We also explore the performance characteristics of breath testing (sensitivity, specificity, positive and negative predictive values, likelihood ratios, and diagnostic odds ratio). Additionally, we describe complementary and alternative tests for diagnosing SIBO. We discuss applications of breath testing for research. Current estimates of SIBO prevalence among commonly encountered high-risk populations are reviewed to provide pretest probability estimates under a variety of clinical situations. Finally, we discuss how to integrate breath test performance characteristics into clinical care decisions using clinical predictors and the Fagan nomogram.
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Affiliation(s)
- Aylin Tansel
- Department of Medicine, Division of Gastroenterology, Hepatology, and Nutrition, University of Pittsburgh Medical Center, Pittsburgh, USA
| | - David J. Levinthal
- Department of Medicine, Division of Gastroenterology, Hepatology, and Nutrition, University of Pittsburgh Medical Center, Pittsburgh, USA
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8
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Dong C, Wang G, Xian R, Li C, Wang S, Cui L. Association between Small Intestinal Bacterial Overgrowth and Subclinical Atheromatous Plaques. J Clin Med 2022; 12:jcm12010314. [PMID: 36615114 PMCID: PMC9821204 DOI: 10.3390/jcm12010314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 12/09/2022] [Accepted: 12/27/2022] [Indexed: 01/03/2023] Open
Abstract
Background: Several recent studies have reported the relationship between atherosclerosis and gut microbial imbalance. Small intestinal bacterial overgrowth (SIBO) is one of the most common forms of gut microbiota imbalance, and studies have shown that SIBO plays an important role in human health. However, the relationship between SIBO and subclinical atheromatous plaques remains unclear. The aim of this study was to investigate the frequency of subclinical atheromatous plaques in patients with SIBO and to explore the association between these two conditions. Methods: A total of 411 eligible subjects were included in this study. The lactulose hydrogen-methane breath test was used to diagnose SIBO, and ultrasound examinations of the carotid, abdominal aorta and lower extremity arteries were performed in all subjects to assess the presence of plaques. Results: Plaques were more common in the SIBO-positive group than in the SIBO-negative group (abdominal aorta, 74.2% vs. 38.8%, p < 0.01; carotid arteries, 71.7% vs. 52.3, p < 0.01; lower extremity arteries, 73.4% vs. 57.6%, p < 0.01). After adjusting for traditional confounders, compared to the SIBO-negative population, the SIBO-positive population had, respectively, OR = 4.18 (95% CI = 2.56−6.80, p < 0.001), OR = 1.93 (95% CI = 1.23−3.02, p = 0.004), OR = 1.81 (95% CI = 1.14−2.88, p = 0.011) and OR = 5.42 (95% CI = 2.78−10.58, p < 0.001) for abdominal, carotid, lower extremity and any-territory plaque presence. Conclusion: SIBO was found to be associated with subclinical atheromatous plaques, and the mechanism of this association warrants further exploration.
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Affiliation(s)
- Changhao Dong
- Department of Gastroenterology, School of Medicine, South China University of Technology, Guangzhou 510006, China
- Department of Gastroenterology, The Sixth Medical Center of PLA General Hospital of Beijing, Beijing 100048, China
| | - Guangxiang Wang
- Department of Gastroenterology, The Sixth Medical Center of PLA General Hospital of Beijing, Beijing 100048, China
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou 510515, China
| | - Rui Xian
- Department of Gastroenterology, School of Medicine, South China University of Technology, Guangzhou 510006, China
- Department of Gastroenterology, The Sixth Medical Center of PLA General Hospital of Beijing, Beijing 100048, China
| | - Chao Li
- Department of Gastroenterology, The Sixth Medical Center of PLA General Hospital of Beijing, Beijing 100048, China
| | - Shaoxin Wang
- Department of Gastroenterology, The Sixth Medical Center of PLA General Hospital of Beijing, Beijing 100048, China
| | - Lihong Cui
- Department of Gastroenterology, School of Medicine, South China University of Technology, Guangzhou 510006, China
- Department of Gastroenterology, The Sixth Medical Center of PLA General Hospital of Beijing, Beijing 100048, China
- Correspondence:
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9
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Hoegenauer C, Hammer HF, Mahnert A, Moissl-Eichinger C. Methanogenic archaea in the human gastrointestinal tract. Nat Rev Gastroenterol Hepatol 2022; 19:805-813. [PMID: 36050385 DOI: 10.1038/s41575-022-00673-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/26/2022] [Indexed: 12/24/2022]
Abstract
The human microbiome is strongly interwoven with human health and disease. Besides bacteria, viruses and eukaryotes, numerous archaea are located in the human gastrointestinal tract and are responsible for methane production, which can be measured in clinical methane breath analyses. Methane is an important readout for various diseases, including intestinal methanogen overgrowth. Notably, the archaea responsible for methane production are largely overlooked in human microbiome studies due to their non-bacterial biology and resulting detection issues. As such, their importance for health and disease remains largely unclear to date, in particular as not a single archaeal representative has been deemed to be pathogenic. In this Perspective, we discuss the current knowledge on the clinical relevance of methanogenic archaea. We explain the archaeal unique response to antibiotics and their negative and positive effects on human physiology, and present the current understanding of the use of methane as a diagnostic marker.
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Affiliation(s)
- Christoph Hoegenauer
- Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Heinz F Hammer
- Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Alexander Mahnert
- Diagnostic and Research Department of Microbiology, Hygiene and Environmental Medicine, Medical University of Graz, Graz, Austria
| | - Christine Moissl-Eichinger
- Diagnostic and Research Department of Microbiology, Hygiene and Environmental Medicine, Medical University of Graz, Graz, Austria.
- BioTechMed Graz, Graz, Austria.
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10
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Bushyhead D, Quigley EMM. Small Intestinal Bacterial Overgrowth-Pathophysiology and Its Implications for Definition and Management. Gastroenterology 2022; 163:593-607. [PMID: 35398346 DOI: 10.1053/j.gastro.2022.04.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 03/28/2022] [Accepted: 04/03/2022] [Indexed: 12/19/2022]
Abstract
The concept of small intestinal bacterial overgrowth (SIBO) arose in the context of maldigestion and malabsorption among patients with obvious risk factors that permitted the small bowel to be colonized by potentially injurious colonic microbiota. Such colonization resulted in clinical signs, symptoms, and laboratory abnormalities that were explicable within a coherent pathophysiological framework. Coincident with advances in medical science, diagnostic testing evolved from small bowel culture to breath tests and on to next-generation, culture-independent microbial analytics. The advent and ready availability of breath tests generated a dramatic expansion in both the rate of diagnosis of SIBO and the range of associated gastrointestinal and nongastrointestinal clinical scenarios. However, issues with the specificity of these same breath tests have clouded their interpretation and aroused some skepticism regarding the role of SIBO in this expanded clinical repertoire. Furthermore, the pathophysiological plausibility that underpins SIBO as a cause of maldigestion/malabsorption is lacking in regard to its purported role in irritable bowel syndrome, for example. One hopes that the application of an ever-expanding armamentarium of modern molecular microbiology to the human small intestinal microbiome in both health and disease will ultimately resolve this impasse and provide an objective basis for the diagnosis of SIBO.
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Affiliation(s)
- Daniel Bushyhead
- Lynda K. and David M. Underwood Center for Digestive Disorders, Division of Gastroenterology and Hepatology, Houston Methodist Hospital and Weill Cornell Medical College, Houston, Texas.
| | - Eamonn M M Quigley
- Lynda K. and David M. Underwood Center for Digestive Disorders, Division of Gastroenterology and Hepatology, Houston Methodist Hospital and Weill Cornell Medical College, Houston, Texas
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