1
|
Campbell A, Gdanetz K, Schmidt AW, Schmidt TM. H 2 generated by fermentation in the human gut microbiome influences metabolism and competitive fitness of gut butyrate producers. MICROBIOME 2023; 11:133. [PMID: 37322527 PMCID: PMC10268494 DOI: 10.1186/s40168-023-01565-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 05/03/2023] [Indexed: 06/17/2023]
Abstract
BACKGROUND Hydrogen gas (H2) is a common product of carbohydrate fermentation in the human gut microbiome and its accumulation can modulate fermentation. Concentrations of colonic H2 vary between individuals, raising the possibility that H2 concentration may be an important factor differentiating individual microbiomes and their metabolites. Butyrate-producing bacteria (butyrogens) in the human gut usually produce some combination of butyrate, lactate, formate, acetate, and H2 in branched fermentation pathways to manage reducing power generated during the oxidation of glucose to acetate and carbon dioxide. We predicted that a high concentration of intestinal H2 would favor the production of butyrate, lactate, and formate by the butyrogens at the expense of acetate, H2, and CO2. Regulation of butyrate production in the human gut is of particular interest due to its role as a mediator of colonic health through anti-inflammatory and anti-carcinogenic properties. RESULTS For butyrogens that contained a hydrogenase, growth under a high H2 atmosphere or in the presence of the hydrogenase inhibitor CO stimulated production of organic fermentation products that accommodate reducing power generated during glycolysis, specifically butyrate, lactate, and formate. Also as expected, production of fermentation products in cultures of Faecalibacterium prausnitzii strain A2-165, which does not contain a hydrogenase, was unaffected by H2 or CO. In a synthetic gut microbial community, addition of the H2-consuming human gut methanogen Methanobrevibacter smithii decreased butyrate production alongside H2 concentration. Consistent with this observation, M. smithii metabolic activity in a large human cohort was associated with decreased fecal butyrate, but only during consumption of a resistant starch dietary supplement, suggesting the effect may be most prominent when H2 production in the gut is especially high. Addition of M. smithii to the synthetic communities also facilitated the growth of E. rectale, resulting in decreased relative competitive fitness of F. prausnitzii. CONCLUSIONS H2 is a regulator of fermentation in the human gut microbiome. In particular, high H2 concentration stimulates production of the anti-inflammatory metabolite butyrate. By consuming H2, gut methanogenesis can decrease butyrate production. These shifts in butyrate production may also impact the competitive fitness of butyrate producers in the gut microbiome. Video Abstract.
Collapse
Affiliation(s)
- Austin Campbell
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Kristi Gdanetz
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI, 48824, USA
| | - Alexander W Schmidt
- Department of Internal Medicine, Division of Infectious Diseases, University of Michigan, MI, 48109, Ann Arbor, USA
| | - Thomas M Schmidt
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, 48109, USA.
- Department of Ecology & Evolutionary Biology, University of Michigan, MI, 48109, Ann Arbor, USA.
- Department of Internal Medicine, Division of Infectious Diseases, University of Michigan, MI, 48109, Ann Arbor, USA.
| |
Collapse
|
2
|
Liu Y, Chu M, Wang D, Luo Y, Liu Z, Zhao J. Risk factors for small intestinal bacterial overgrowth in patients with acute ischaemic stroke. J Med Microbiol 2023; 72. [PMID: 36762525 DOI: 10.1099/jmm.0.001666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
Abstract
Introduction. The intestinal flora has become a promising new target in acute ischaemic stroke (AIS), and small intestinal bacterial overgrowth (SIBO) is a common pathological condition of the intestinal flora. Recently, the lactose hydrogen-methane breath test has emerged as a non-invasive and economical method for the detection of SIBO in AIS patients. Exploring the prevalence of SIBO and its associated risk factors will provide a clinical basis for the association between intestinal flora and AIS.Hypothesis/Gap Statement. Given that the prevalence of SIBO and its risk factors in patients with AIS remain to be studied, there is a need to investigate them.Aim. This study aimed to investigate the prevalence and risk factors of SIBO in patients with AISMethodology. Eighty patients tested for SIBO using the lactulose hydrogen-methane breath test were evaluated. Patients were divided into SIBO-positive and SIBO-negative groups according to the presence or absence of SIBO, respectively. The baseline characteristics and clinical biochemical indicators of the patients were compared between the two groups. The independent risk factors and predictive value of SIBO in AIS patients were determined using multivariate logistic regression and receiver operating characteristic (ROC) curve analyses.Results. Of the 80 consecutive patients with AIS, 23 (28.8 %) tested positive for SIBO. Triglyceride (TG) and homocysteine (Hcy) levels were identified as independent risk factors for SIBO in patients with AIS using multivariate logistic regression analysis (P<0.005). ROC curve analysis showed that the area under the curve (AUC) of TG was 0.690 (95 % CI 0.577-0.789, P=0.002). The sensitivity, specificity and optimal cut-off values were 95.7 %, 35.1 % and 1.14 mmol l-1, respectively. The AUC of Hcy was 0.676 (95 % CI 0.562-0.776, P=0.01). The sensitivity, specificity and optimal cut-off values were 73.9 %, 59.7 % and 14.1 µmol-1, respectively. When TG and Hcy levels were combined, the AUC increased to 0.764 (95 % CI 0.656-0.852, P<0.001). The specificity and sensitivity were 61.4 and 82.6 %, respectively. This showed that the combined detection of TG and Hcy levels had a higher predictive valueConclusion. The prevalence of SIBO in patients with AIS was 28.8 %. TG and Hcy levels are independent risk factors for SIBO in patients with AIS. Both markers had good predictive value for the occurrence of SIBO. In the future, we should actively utilize these indicators to prevent intestinal flora imbalance and the occurrence of SIBO.
Collapse
Affiliation(s)
- Yang Liu
- Department of Neurology, Minhang Hospital, Fudan University, Shanghai, PR China
| | - Min Chu
- Department of Neurology, Minhang Hospital, Fudan University, Shanghai, PR China
| | - Daosheng Wang
- Department of Neurosurgery, Minhang Hospital, Fudan University, Shanghai, PR China
| | - Yunhe Luo
- Department of Neurology, Minhang Hospital, Fudan University, Shanghai, PR China
| | - Zhuohang Liu
- Department of Neurology, Minhang Hospital, Fudan University, Shanghai, PR China
| | - Jing Zhao
- Department of Neurology, Minhang Hospital, Fudan University, Shanghai, PR China
| |
Collapse
|
3
|
Karas D, Bužga M, Stejskal D, Kocna P, Holéczy P, Novotná A, Švagera Z. Breath Tests Used in the Context of Bariatric Surgery. Diagnostics (Basel) 2022; 12:diagnostics12123170. [PMID: 36553178 PMCID: PMC9777764 DOI: 10.3390/diagnostics12123170] [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: 09/23/2022] [Revised: 12/01/2022] [Accepted: 12/11/2022] [Indexed: 12/23/2022] Open
Abstract
This review article focuses on the use of breath tests in the field of bariatrics and obesitology. The first part of the review is an introduction to breath test problematics with a focus on their use in bariatrics. The second part provides a brief history of breath testing. Part three describes how breath tests are used for monitoring certain processes in various organs and various substances in exhaled air and how the results are analyzed and evaluated. The last part covers studies that described the use of breath tests for monitoring patients that underwent bariatric treatments. Although the number of relevant studies is small, this review could promote the future use of breath testing in the context of bariatric treatments.
Collapse
Affiliation(s)
- Daniel Karas
- Institute of Laboratory Medicine, Faculty of Medicine, University of Ostrava, Syllabova 19, 703 00 Ostrava, Czech Republic
| | - Marek Bužga
- Department of Human Movement Studies, Faculty of Education, University of Ostrava, Fráni Šrámka 3, 709 00 Ostrava, Czech Republic
- Department of Physiology and Pathophysiology, Faculty of Medicine, University of Ostrava, Syllabova 19, 703 00 Ostrava, Czech Republic
- Institute of Laboratory Medicine, University Hospital Ostrava, 17. Listopadu 1790/5, 708 52 Ostrava, Czech Republic
- Correspondence:
| | - David Stejskal
- Institute of Laboratory Medicine, Faculty of Medicine, University of Ostrava, Syllabova 19, 703 00 Ostrava, Czech Republic
- Institute of Laboratory Medicine, University Hospital Ostrava, 17. Listopadu 1790/5, 708 52 Ostrava, Czech Republic
| | - Petr Kocna
- Institute of Medical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine, Charles University in Prague, Kateřinská 1660/32, 121 08 Prague, Czech Republic
| | - Pavol Holéczy
- Department of Surgery, Vítkovice Hospital, Zalužanského 1192/15, 703 00 Ostrava, Czech Republic
- Department of Surgical Disciplines, Faculty of Medicine, University of Ostrava, Syllabova 19, 703 00 Ostrava, Czech Republic
| | - Adéla Novotná
- Department of Epidemiology and Public Health, Faculty of Medicine, University of Ostrava, Syllabova 19, 703 00 Ostrava, Czech Republic
| | - Zdeněk Švagera
- Institute of Laboratory Medicine, Faculty of Medicine, University of Ostrava, Syllabova 19, 703 00 Ostrava, Czech Republic
- Institute of Laboratory Medicine, University Hospital Ostrava, 17. Listopadu 1790/5, 708 52 Ostrava, Czech Republic
| |
Collapse
|
4
|
Archaeome in Colorectal Cancer: High Abundance of Methanogenic Archaea in Colorectal Cancer Patients. INTERNATIONAL JOURNAL OF CANCER MANAGEMENT 2022. [DOI: 10.5812/ijcm-117843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background: The importance of microbiome in the progression and development of colorectal cancer (CRC) has been discussed in the last decade. Like colon bacteria, other intestinal microorganisms, including archaea, could also be involved in the CRC progression, so it's important to work out the archaeal microbiome (archaeome) composition among CRC patients. Objectives: The aim of this study was to determine the archaeome composition of CRC and healthy controls based on age and gender. Methods: Total bacterial DNA was extracted from 30 biopsy samples (17 CRC and 13 healthy controls). Archaeome communities were profiled by 16S rRNA high throughput sequencing, then compared to clinicopathological features, including CRC patients’ gender and age. Results: In the CRC patients, archaeal methanogens including Methanobrevibacter (86%) and Methanomassiliicoccus (8%) were overrepresented at the genus level. In contrast in the healthy controls, only two genera of haloarchaea including Natronococcus (58%) and Haloterrigena (42%) were presented. The results showed that the number of archaeal genera in men is higher than women in both the CRC and healthy controls. moreover, our results showed that the most genera of archaea are present in the CRC-32-50 group, six archaeal genera. The differential abundance taxa analysis results showed significant differences between healthy controls and CRC patients (P ≤ 0.05). Conclusions: The high abundance of methanogens in the colon archaeome of CRC patients compared to healthy controls suggests that methanogens may be involved in CRC development.
Collapse
|
5
|
Kumpitsch C, Fischmeister FPS, Mahnert A, Lackner S, Wilding M, Sturm C, Springer A, Madl T, Holasek S, Högenauer C, Berg IA, Schoepf V, Moissl-Eichinger C. Reduced B12 uptake and increased gastrointestinal formate are associated with archaeome-mediated breath methane emission in humans. MICROBIOME 2021; 9:193. [PMID: 34560884 PMCID: PMC8464155 DOI: 10.1186/s40168-021-01130-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 07/06/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Methane is an end product of microbial fermentation in the human gastrointestinal tract. This gas is solely produced by an archaeal subpopulation of the human microbiome. Increased methane production has been associated with abdominal pain, bloating, constipation, IBD, CRC or other conditions. Twenty percent of the (healthy) Western populations innately exhale substantially higher amounts (>5 ppm) of this gas. The underlying principle for differential methane emission and its effect on human health is not sufficiently understood. RESULTS We assessed the breath methane content, the gastrointestinal microbiome, its function and metabolome, and dietary intake of one-hundred healthy young adults (female: n = 52, male: n = 48; mean age =24.1). On the basis of the amount of methane emitted, participants were grouped into high methane emitters (CH4 breath content 5-75 ppm) and low emitters (CH4 < 5 ppm). The microbiomes of high methane emitters were characterized by a 1000-fold increase in Methanobrevibacter smithii. This archaeon co-occurred with a bacterial community specialized on dietary fibre degradation, which included members of Ruminococcaceae and Christensenellaceae. As confirmed by metagenomics and metabolomics, the biology of high methane producers was further characterized by increased formate and acetate levels in the gut. These metabolites were strongly correlated with dietary habits, such as vitamin, fat and fibre intake, and microbiome function, altogether driving archaeal methanogenesis. CONCLUSIONS This study enlightens the complex, multi-level interplay of host diet, genetics and microbiome composition/function leading to two fundamentally different gastrointestinal phenotypes and identifies novel points of therapeutic action in methane-associated disorders. Video Abstract.
Collapse
Affiliation(s)
- Christina Kumpitsch
- Diagnostic and Research Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Neue Stiftingtalstraße 6, 8010 Graz, Austria
| | - Florian Ph. S. Fischmeister
- Department of Psychology, University of Graz, 8010 Graz, Austria
- Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, 1090 Vienna, Austria
| | - Alexander Mahnert
- Diagnostic and Research Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Neue Stiftingtalstraße 6, 8010 Graz, Austria
| | - Sonja Lackner
- Division of Immunology and Pathophysiology, Medical University of Graz, 8010 Graz, Austria
| | - Marilena Wilding
- Department of Psychology, University of Graz, 8010 Graz, Austria
| | - Corina Sturm
- Department of Psychology, University of Graz, 8010 Graz, Austria
| | - Anna Springer
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology & Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Tobias Madl
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology & Biochemistry, Medical University of Graz, 8010 Graz, Austria
- BioTechMed, 8010 Graz, Austria
| | - Sandra Holasek
- Division of Immunology and Pathophysiology, Medical University of Graz, 8010 Graz, Austria
| | - Christoph Högenauer
- Division of Gastroenterology and Hepatology, Medical University of Graz, Graz, Austria
| | - Ivan A. Berg
- Institute for Molecular Microbiology and Biotechnology, University of Münster, Münster, Germany
| | - Veronika Schoepf
- Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, 1090 Vienna, Austria
| | - Christine Moissl-Eichinger
- Diagnostic and Research Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Neue Stiftingtalstraße 6, 8010 Graz, Austria
- BioTechMed, 8010 Graz, Austria
| |
Collapse
|
6
|
Hydrogen and Methane Breath Test in the Diagnosis of Lactose Intolerance. Nutrients 2021; 13:nu13093261. [PMID: 34579138 PMCID: PMC8472045 DOI: 10.3390/nu13093261] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/29/2021] [Accepted: 09/15/2021] [Indexed: 12/31/2022] Open
Abstract
The hydrogen (H2) breath test is a non-invasive investigation used to diagnose lactose intolerance (LI). Patients with LI may also expire increased amounts of methane (CH4) during a lactose test. The aim of this study is to evaluate the contribution of CH4 measurements. We tested 209 children (1–17 years old) with symptoms suggesting LI with lactose H2 and CH4 breath tests. The result was positive when the H2 excretion exceeded 20 parts per million (ppm) and the CH4 was 10 ppm above the baseline. A clinician, blinded for the results of the breath test, registered the symptoms. Of the patient population, 101/209 (48%) were negative for both H2 and CH4; 96/209 (46%) had a positive H2 breath test result; 31/96 (32%) were also positive for CH4; 12/209 (6%) patients were only positive for CH4. The majority of hydrogen producers showed symptoms, whereas this was only the case in half of the H2-negative CH4 producers. Almost all patients treated with a lactose-poor diet reported significant symptom improvement. These results indicate that CH4 measurements may possibly be of additional value for the diagnosis of LI, since 5.7% of patients were negative for H2 and positive for CH4, and half of them experienced symptoms during the test.
Collapse
|
7
|
Oral Iron Supplementation—Gastrointestinal Side Effects and the Impact on the Gut Microbiota. MICROBIOLOGY RESEARCH 2021. [DOI: 10.3390/microbiolres12020033] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Iron deficiency anaemia (IDA) is a worldwide healthcare problem affecting approximately 25% of the global population. The most common IDA treatment is oral iron supplementation, which has been associated with gastrointestinal (GI) side effects such as constipation and bloating. These can result in treatment non-adherence and the persistence of IDA. Intravenous iron does not cause GI side effects, which may be due to the lack of exposure to the intestinal lumen. Luminal iron can cause changes to the gut microbiota, aiding the promotion of pathogenic species and decreasing beneficial protective species. Iron is vital for methanogenic archaea, which rely on iron for growth and metabolism. Increased intestinal methane has been associated with slowing of intestinal transit, constipation, and bloating. Here we explore the literature to understand a potential link between iron and methanogenesis as a novel way to understand the mechanism of oral iron supplementation induced GI side effects.
Collapse
|
8
|
Song Y, Liu Y, Qi B, Cui X, Dong X, Wang Y, Han X, Li F, Shen D, Zhang X, Hu K, Chen S, Zhou J, Ge J. Association of Small Intestinal Bacterial Overgrowth With Heart Failure and Its Prediction for Short-Term Outcomes. J Am Heart Assoc 2021; 10:e015292. [PMID: 33728933 PMCID: PMC8174348 DOI: 10.1161/jaha.119.015292] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Background Small intestinal bacterial overgrowth (SIBO) is a common pathological condition of intestinal microbiota. The prevalence of SIBO and its prognostic value in patients with heart failure (HF) are unknown. Methods and Results A total of 287 patients tested for SIBO using lactulose hydrogen-methane breath test were evaluated. At least 1 of the following criteria fulfilled was SIBO positive: patients with fasting hydrogen level ≥20 parts per million (ppm) or a ≥20 ppm rise in hydrogen by 90 minutes were diagnosed with SIBO (H2) positive; and patients with methane levels ≥10 ppm at any test point were diagnosed with SIBO (CH4) positive. The association between SIBO and the composite of cardiovascular death and HF rehospitalization was investigated. In 287 consecutive patients with HF, 128 (45%) were positive for SIBO. Our result showed SIBO increased the risk of HF rehospitalization in patients with HF with reduced ejection fraction (P<0.001), and the risk of cardiovascular death in patients with HF with preserved EF (P=0.011). SIBO was an independent risk factor of primary end point in patients with HF (hazard ratio [HR], 2.13; 95% CI; 1.26-3.58; P=0.005). In addition, SIBO (CH4) showed a prognostic value on adverse outcomes (HR, 2.35; 95% CI, 1.38-4.02; P<0.001), whereas the association between SIBO (H2) and outcomes was not statistically significant. Conclusions There was high prevalence of SIBO in patients with HF, and SIBO was independently associated with poor outcomes. Proactive treatment for SIBO may provide extra benefit for patients with HF.
Collapse
Affiliation(s)
- Yu Song
- Department of Cardiology Shanghai Institute of Cardiovascular DiseasesZhongshan HospitalFudan University Shanghai China
| | - Yuan Liu
- Department of Cardiology Shanghai Institute of Cardiovascular DiseasesZhongshan HospitalFudan University Shanghai China
| | - Baozhen Qi
- Department of Cardiology Shanghai Institute of Cardiovascular DiseasesZhongshan HospitalFudan University Shanghai China
| | - Xiaotong Cui
- Department of Cardiology Shanghai Institute of Cardiovascular DiseasesZhongshan HospitalFudan University Shanghai China
| | - Xinyue Dong
- Department of Cardiology Zhongshan HospitalFudan University Shanghai China
| | - Yanyan Wang
- Department of Cardiology Shanghai Institute of Cardiovascular DiseasesZhongshan HospitalFudan University Shanghai China
| | - Xueting Han
- Department of Cardiology Shanghai Institute of Cardiovascular DiseasesZhongshan HospitalFudan University Shanghai China
| | - Fuhai Li
- Department of Cardiology Shanghai Institute of Cardiovascular DiseasesZhongshan HospitalFudan University Shanghai China
| | - Dongli Shen
- Department of Cardiology Shanghai Institute of Cardiovascular DiseasesZhongshan HospitalFudan University Shanghai China
| | - Xian Zhang
- Department of Cardiology Zhongshan HospitalFudan University Shanghai China
| | - Kai Hu
- Department of Cardiology Shanghai Institute of Cardiovascular DiseasesZhongshan HospitalFudan University Shanghai China
| | - Shiyao Chen
- Department of Gastroenterology and Hepatology Zhongshan HospitalFudan University Shanghai China
| | - Jingmin Zhou
- Department of Cardiology Shanghai Institute of Cardiovascular DiseasesZhongshan HospitalFudan University Shanghai China
| | - Junbo Ge
- Department of Cardiology Shanghai Institute of Cardiovascular DiseasesZhongshan HospitalFudan University Shanghai China
| |
Collapse
|
9
|
Hydrogen-methane breath testing results influenced by oral hygiene. Sci Rep 2021; 11:26. [PMID: 33420116 PMCID: PMC7794545 DOI: 10.1038/s41598-020-79554-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 12/07/2020] [Indexed: 12/28/2022] Open
Abstract
The measurement of hydrogen–methane breath gases is widely used in gastroenterology to evaluate malabsorption syndromes and bacterial overgrowth. Laboratories offering breath testing provide variable guidance regarding oral hygiene practices prior to testing. Given that oral dysbiosis has the potential to cause changes in breath gases, it raises concerns that oral hygiene is not a standard inclusion in current breath testing guidelines. The aim of this study was to determine how a pre-test mouthwash may impact hydrogen–methane breath test results. Participants presenting for breath testing who had elevated baseline gases were given a chlorhexidine mouthwash. If a substantial reduction in expired hydrogen or methane occurred after the mouthwash, breath samples were collected before and after a mouthwash at all breath sample collection points for the duration of testing. Data were evaluated to determine how the mouthwash might influence test results and diagnostic status. In 388 consecutive hydrogen–methane breath tests, modifiable elevations occurred in 24.7%. Administration of a chlorhexidine mouthwash resulted in significantly (p ≤ 0.05) reduced breath hydrogen in 67% and/or methane gas in 93% of those consenting to inclusion. In some cases, this modified the diagnosis. Mean total gas concentrations pre- and post-mouthwash were 221.0 ppm and 152.1 ppm (p < 0.0001) for hydrogen, and 368.9 ppm and 249.8 ppm (p < 0.0001) for methane. Data suggest that a single mouthwash at baseline has a high probability of returning a false positive diagnosis. Variations in gas production due to oral hygiene practices has significant impacts on test interpretation and the subsequent diagnosis. The role of oral dysbiosis in causing gastrointestinal symptoms also demands exploration as it may be an underlying factor in the presenting condition that was the basis for the referral.
Collapse
|
10
|
Dharmawardana N, Goddard T, Woods C, Watson DI, Butler R, Ooi EH, Yazbeck R. Breath methane to hydrogen ratio as a surrogate marker of intestinal dysbiosis in head and neck cancer. Sci Rep 2020; 10:15010. [PMID: 32929151 PMCID: PMC7490703 DOI: 10.1038/s41598-020-72115-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 08/13/2020] [Indexed: 01/30/2023] Open
Abstract
Exhaled breath compounds can non-invasively detect head and neck squamous cell carcinoma (HNSCC). Here we investigated exhaled compounds related to intestinal bacterial carbohydrate fermentation. Fasting breath samples were collected into 3 litre FlexFoil PLUS bags from patients awaiting a biopsy procedure for suspected HNSCC. Samples were analysed using a Syft selected ion flow-tube mass spectrometer and a Quintron BreathTracker. Two tailed non-parametric significance testing was conducted with corrections for multiple imputations. 74 patients were diagnosed (histological) with HNSCC and 61 patients were benign (controls). The methane to hydrogen ratio was significantly different between cancer and non-cancer controls (p = 0.0440). This ratio increased with tumour stage with a significant difference between T1 and T4 tumours (p = 0.0259). Hydrogen levels were significantly higher in controls who were smokers (p = 0.0129), with no smoking dependent methane changes. There were no differences in short chain fatty acids between groups. Exhaled compounds of intestinal carbohydrate fermentation can detect HNSCC patients. These findings suggest a modified carbohydrate fermentation profile in HNSCC patients that is tumour stage and smoking status dependent.
Collapse
Affiliation(s)
- Nuwan Dharmawardana
- Department of Otorhinolaryngology-Head and Neck Surgery, Flinders Medical Centre, Bedford Park, Australia. .,Discipline of Surgery, College of Medicine and Public Health, Flinders University, Bedford Park, Australia.
| | - Thomas Goddard
- Department of Respiratory and Sleep Medicine, Women's and Children's Hospital, Adelaide, Australia
| | - Charmaine Woods
- Department of Otorhinolaryngology-Head and Neck Surgery, Flinders Medical Centre, Bedford Park, Australia.,Discipline of Surgery, College of Medicine and Public Health, Flinders University, Bedford Park, Australia
| | - David I Watson
- Discipline of Surgery, College of Medicine and Public Health, Flinders University, Bedford Park, Australia
| | - Ross Butler
- Discipline of Surgery, College of Medicine and Public Health, Flinders University, Bedford Park, Australia
| | - Eng H Ooi
- Department of Otorhinolaryngology-Head and Neck Surgery, Flinders Medical Centre, Bedford Park, Australia.,Discipline of Surgery, College of Medicine and Public Health, Flinders University, Bedford Park, Australia
| | - Roger Yazbeck
- Discipline of Surgery, College of Medicine and Public Health, Flinders University, Bedford Park, Australia
| |
Collapse
|
11
|
Harvie RM, Tuck CJ, Schultz M. Evaluation of lactulose, lactose, and fructose breath testing in clinical practice: A focus on methane. JGH OPEN 2019; 4:198-205. [PMID: 32280765 PMCID: PMC7144793 DOI: 10.1002/jgh3.12240] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 07/13/2019] [Indexed: 12/17/2022]
Abstract
Background and Aim Breath testing (BT) is used to identify carbohydrate malabsorption and small intestine bacterial overgrowth. Measuring methane alongside hydrogen is advocated to reduce false-negative studies, but the variability of methane production is unknown. The aim of this study is to examine the effect of high methane production on hydrogen excretion after ingesting lactulose, fructose, or lactose. Methods A retrospective audit was performed of patients with gastrointestinal symptoms who underwent BT. Following a low fermentable carbohydrate diet for 24-h, a fasting BT before consuming 35 ml lactulose, 35 g fructose, or lactose in 200 ml water, followed by BT every 10-15 min for up to 3-h, was performed. A positive test was defined as a ≥20 ppm rise of hydrogen or methane from baseline. A high methane producer had an initial reading of ≥5 ppm. Breath hydrogen and methane production were measured as area under the curve. Chi-squared tests were used to compare proportions of those meeting the cut-off criteria. Results Of patients, 26% (28/106) were high methane producers at their initial lactulose test. The test-retest repeatability of methane production was high, with the same methane production status before ingesting lactose in all (70/70) and before ingesting fructose in most (71/73). Methane production was highly variable during testing, with 38% (10/26) having ≥1 reading lower than baseline. Hydrogen produced by high or low methane producers did not differ (1528 [960-3645] ppm min vs 2375 [1810-3195] ppm min [P = 0.11]). Symptoms and breath test results were not positively related. Conclusion The validity of including an increase of ≥20 ppm methane to identify carbohydrate malabsorption or small intestine bacterial overgrowth should be questioned due to the variability of readings during testing.
Collapse
Affiliation(s)
- Ruth M Harvie
- Department of Medicine, Dunedin School of Medicine University of Otago Dunedin New Zealand
| | - Caroline J Tuck
- Gastrointestinal Disease Research Unit, Kingston General Hospital Queen's University Kingston Ontario Canada
| | - Michael Schultz
- Department of Medicine, Dunedin School of Medicine University of Otago Dunedin New Zealand.,Gastroenterology Otago Ltd., Marinoto Clinic Mercy Hospital Dunedin New Zealand
| |
Collapse
|
12
|
Bin Waqar SH, Rehan A. Methane and Constipation-predominant Irritable Bowel Syndrome: Entwining Pillars of Emerging Neurogastroenterology. Cureus 2019; 11:e4764. [PMID: 31363445 PMCID: PMC6663118 DOI: 10.7759/cureus.4764] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Functional gut disorders have long known to cause depravity in quality of life. Among the group of these heterogeneous disorders, irritable bowel syndrome (IBS) has been known to affect a large chunk of our population. IBS is not as simple as it sounds. Caused by a multitude of factors, the heterogeneity of this disorder has laid the foundation for research and the new principles of neurogastroenterology. Dysbiosis and methane production are one of the forthcoming factors that are currently under investigation. Down the road of exclusive enteric anaerobic fermentation of polysaccharides, methane is produced. It was considered to be an inert gas in the past, with little to no role in gut activity but now it is established that it has an impressive role in the etiology of constipation-predominant IBS (C-IBS). Acting as a neurotransmitter, it is known to affect ileal and colonic transit time, which has currently been shown in animal studies. Many laxatives, ionophore antibiotics, drugs like rifamixin and neomycin have been targeted against this very principle. Lately, lovastatin has emerged as a potential pharmacologic therapy to devoid the gut of methane without disrupting the gut niche in itself and has shown promise in relieving the symptoms of C-IBS. The goal of this article is to compile and assemble the literature available on IBS and the neuromodulation of methane to teach physicians and research scientists about the current age of gastroenterology and the growing need to emphasize the role of methane in the symptomatology of functional gut disorders like C-IBS.
Collapse
Affiliation(s)
| | - Aiman Rehan
- Internal Medicine, Dow University of Health Sciences, Karachi, PAK
| |
Collapse
|
13
|
The human archaeome: methodological pitfalls and knowledge gaps. Emerg Top Life Sci 2018; 2:469-482. [PMID: 33525835 DOI: 10.1042/etls20180037] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 09/20/2018] [Accepted: 10/01/2018] [Indexed: 02/07/2023]
Abstract
Forty years ago, archaea were described as a separate domain of life, distinct from bacteria and eukarya. Although it is known for quite a long time that methanogenic archaea are substantial components of the human gastrointestinal tract (GIT) and the oral cavity, the knowledge on the human archaeome is very limited. Various methodological problems contribute to the invisibility of the human archaeome, resulting in severe knowledge gaps and contradictory information. Similar to the bacteriome, the archaeal biogeography was found to be site-specific, forming (i) the thaumarchaeal skin landscape, (ii) the (methano)euryarchaeal GIT landscape, (iii) a mixed skin/GIT landscape in nose, and (iv) a woesearchaeal lung landscape, including numerous unknown archaeal clades. Compared with so-called universal microbiome approaches, archaea-specific protocols reveal a wide diversity and high quantity of archaeal signatures in various human tissues, with up to 1 : 1 ratios of bacteria and archaea in appendix and nose samples. The archaeome interacts closely with the bacteriome and the human body cells, whereas the roles of the human-associated archaea with respect to human health are only sparsely described. Methanogenic archaea and methane production were correlated with many health issues, including constipation, periodontitis and multiple sclerosis. However, one of the most burning questions - do archaeal pathogens exist? - still remains obscure to date.
Collapse
|