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Banerjee N, Gang SS, Castelletto ML, Ruiz F, Hallem EA. Carbon dioxide shapes parasite-host interactions in a human-infective nematode. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.28.587273. [PMID: 38585813 PMCID: PMC10996684 DOI: 10.1101/2024.03.28.587273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Skin-penetrating nematodes infect nearly one billion people worldwide. The developmentally arrested infective larvae (iL3s) seek out hosts, invade hosts via skin penetration, and resume development inside the host in a process called activation. Activated infective larvae (iL3as) traverse the host body, ending up as parasitic adults in the small intestine. Skin-penetrating nematodes respond to many chemosensory cues, but how chemosensation contributes to host seeking, intra-host development, and intra-host navigation - three crucial steps of the parasite-host interaction - remains poorly understood. Here, we investigate the role of carbon dioxide (CO2) in promoting parasite-host interactions in the human-infective threadworm Strongyloides stercoralis. We show that S. stercoralis exhibits life-stage-specific preferences for CO2: iL3s are repelled, non-infective larvae and adults are neutral, and iL3as are attracted. CO2 repulsion in iL3s may prime them for host seeking by stimulating dispersal from host feces, while CO2 attraction in iL3as may direct worms toward high-CO2 areas of the body such as the lungs and intestine. We also identify sensory neurons that detect CO2; these neurons are depolarized by CO2 in iL3s and iL3as. In addition, we demonstrate that the receptor guanylate cyclase Ss-GCY-9 is expressed specifically in CO2-sensing neurons and is required for CO2-evoked behavior. Ss-GCY-9 also promotes activation, indicating that a single receptor can mediate both behavioral and physiological responses to CO2. Our results illuminate chemosensory mechanisms that shape the interaction between parasitic nematodes and their human hosts and may aid in the design of novel anthelmintics that target the CO2-sensing pathway.
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Affiliation(s)
- Navonil Banerjee
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095
| | - Spencer S. Gang
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095
| | - Michelle L. Castelletto
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095
| | - Felicitas Ruiz
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095
| | - Elissa A. Hallem
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095
- Lead contact
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Gunn D, Abbas Z, Harris HC, Major G, Hoad C, Gowland P, Marciani L, Gill SK, Warren FJ, Rossi M, Remes-Troche JM, Whelan K, Spiller RC. Psyllium reduces inulin-induced colonic gas production in IBS: MRI and in vitro fermentation studies. Gut 2022; 71:919-927. [PMID: 34353864 PMCID: PMC8995815 DOI: 10.1136/gutjnl-2021-324784] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 07/08/2021] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Health-promoting dietary fibre including inulin often triggers gastrointestinal symptoms in patients with IBS, limiting their intake. Our aim was to test if coadministering psyllium with inulin would reduce gas production. DESIGN A randomised, four-period, four-treatment, placebo-controlled, crossover trial in 19 patients with IBS. Subjects ingested a 500 mL test drink containing either inulin 20 g, psyllium 20 g, inulin 20 g+ psyllium 20 g or dextrose 20 g (placebo). Breath hydrogen was measured every 30 min with MRI scans hourly for 6 hours. Faecal samples from a subset of the patients with IBS were tested using an in vitro fermentation model. Primary endpoint was colonic gas assessed by MRI. RESULTS Colonic gas rose steadily from 0 to 6 hours, with inulin causing the greatest rise, median (IQR) AUC(0-360 min) 3145 (848-6502) mL·min. This was significantly reduced with inulin and psyllium coadministration to 618 (62-2345) mL·min (p=0.02), not significantly different from placebo. Colonic volumes AUC(0-360 min) were significantly larger than placebo for both inulin (p=0.002) and inulin and psyllium coadministration (p=0.005). Breath hydrogen rose significantly from 120 min after inulin but not psyllium; coadministration of psyllium with inulin delayed and reduced the maximum increase, AUC(0-360 min) from 7230 (3255-17910) ppm·hour to 1035 (360-4320) ppm·hour, p=0.007.Fermentation in vitro produced more gas with inulin than psyllium. Combining psyllium with inulin did not reduce gas production. CONCLUSIONS Psyllium reduced inulin-related gas production in patients with IBS but does not directly inhibit fermentation. Whether coadministration with psyllium increases the tolerability of prebiotics in IBS warrants further study. TRIAL REGISTRATION NUMBER NCT03265002.
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Affiliation(s)
- David Gunn
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK.,Nottingham Digestive Diseases Centre, University of Nottingham, Nottingham, UK
| | - Zainab Abbas
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK.,Nottingham Digestive Diseases Centre, University of Nottingham, Nottingham, UK
| | - Hannah C Harris
- Food, Innovation and Health, Quadram Institute Bioscience, Norwich, UK
| | - Giles Major
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK.,Nottingham Digestive Diseases Centre, University of Nottingham, Nottingham, UK
| | - Caroline Hoad
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK.,Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, UK
| | - Penny Gowland
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK.,Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, UK
| | - Luca Marciani
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK.,Nottingham Digestive Diseases Centre, University of Nottingham, Nottingham, UK
| | - Samantha K Gill
- Department of Nutritional Sciences, King's College London, London, UK
| | - Fred J Warren
- Food, Innovation and Health, Quadram Institute Bioscience, Norwich, UK
| | - Megan Rossi
- Department of Nutritional Sciences, King's College London, London, UK
| | | | - Kevin Whelan
- Department of Nutritional Sciences, King's College London, London, UK
| | - Robin C Spiller
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK .,Nottingham Digestive Diseases Centre, University of Nottingham, Nottingham, UK
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Screening dietary fibres for fermentation characteristics and metabolic profiles using a rapid in vitro approach: implications for irritable bowel syndrome. Br J Nutr 2020; 126:208-218. [PMID: 33028442 DOI: 10.1017/s0007114520003943] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The therapeutic value of specific fibres is partly dependent on their fermentation characteristics. Some fibres are rapidly degraded with the generation of gases that induce symptoms in patients with irritable bowel syndrome (IBS), while more slowly or non-fermentable fibres may be more suitable. More work is needed to profile a comprehensive range of fibres to determine suitability for IBS. Using a rapid in vitro fermentation model, gas production and metabolite profiles of a range of established and novel fibres were compared. Fibre substrates (n 15) were added to faecal slurries from three healthy donors for 4 h with gas production measured using real-time headspace sampling. Concentrations of SCFA and ammonia were analysed using GC and enzymatic assay, respectively. Gas production followed three patterns: rapid (≥60 ml/g over 4 h) for fructans, carrot fibre and maize-derived xylo-oligosaccharide (XOS); mild (30-60 ml/g) for partially hydrolysed guar gum, almond shell-derived XOS and one type of high-amylose resistant starch 2 (RS2) and minimal (no differences with blank controls) for methylcellulose, another high-amylose RS2, acetylated or butyrylated RS2, RS4, acacia gum and sugarcane bagasse. Gas production correlated positively with total SCFA (r 0·80, P < 0·001) and negatively with ammonia concentrations (r -0·68, P < 0·001). Proportions of specific SCFA varied: fermentation of carrot fibre, XOS and acetylated RS2 favoured acetate, while fructans favoured butyrate. Gas production and metabolite profiles differed between fibre types and within fibre classes over a physiologically relevant 4-h time course. Several fibres resisted rapid fermentation and may be candidates for clinical trials in IBS patients.
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Holmes ZC, Silverman JD, Dressman HK, Wei Z, Dallow EP, Armstrong SC, Seed PC, Rawls JF, David LA. Short-Chain Fatty Acid Production by Gut Microbiota from Children with Obesity Differs According to Prebiotic Choice and Bacterial Community Composition. mBio 2020; 11:e00914-20. [PMID: 32788375 PMCID: PMC7439474 DOI: 10.1128/mbio.00914-20] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 07/13/2020] [Indexed: 12/20/2022] Open
Abstract
Pediatric obesity remains a public health burden and continues to increase in prevalence. The gut microbiota plays a causal role in obesity and is a promising therapeutic target. Specifically, the microbial production of short-chain fatty acids (SCFA) from the fermentation of otherwise indigestible dietary carbohydrates may protect against pediatric obesity and metabolic syndrome. Still, it has not been demonstrated that therapies involving microbiota-targeting carbohydrates, known as prebiotics, will enhance gut bacterial SCFA production in children and adolescents with obesity (age, 10 to 18 years old). Here, we used an in vitro system to examine the SCFA production by fecal microbiota from 17 children with obesity when exposed to five different commercially available over-the-counter (OTC) prebiotic supplements. We found microbiota from all 17 patients actively metabolized most prebiotics. Still, supplements varied in their acidogenic potential. Significant interdonor variation also existed in SCFA production, which 16S rRNA sequencing supported as being associated with differences in the host microbiota composition. Last, we found that neither fecal SCFA concentration, microbiota SCFA production capacity, nor markers of obesity positively correlated with one another. Together, these in vitro findings suggest the hypothesis that OTC prebiotic supplements may be unequal in their ability to stimulate SCFA production in children and adolescents with obesity and that the most acidogenic prebiotic may differ across individuals.IMPORTANCE Pediatric obesity remains a major public health problem in the United States, where 17% of children and adolescents are obese, and rates of pediatric "severe obesity" are increasing. Children and adolescents with obesity face higher health risks, and noninvasive therapies for pediatric obesity often have limited success. The human gut microbiome has been implicated in adult obesity, and microbiota-directed therapies can aid weight loss in adults with obesity. However, less is known about the microbiome in pediatric obesity, and microbiota-directed therapies are understudied in children and adolescents. Our research has two important findings: (i) dietary prebiotics (fiber) result in the microbiota from adolescents with obesity producing more SCFA, and (ii) the effectiveness of each prebiotic is donor dependent. Together, these findings suggest that prebiotic supplements could help children and adolescents with obesity, but that these therapies may not be "one size fits all."
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Affiliation(s)
- Zachary C Holmes
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Justin D Silverman
- Program in Computational Biology and Bioinformatics, Duke University, Durham, North Carolina, USA
- Medical Scientist Training Program, Duke University School of Medicine, Durham, North Carolina, USA
| | - Holly K Dressman
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, USA
- Duke Microbiome Shared Resource, Center for Genomic and Computational Biology, Duke University, Durham, North Carolina, USA
| | - Zhengzheng Wei
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Eric P Dallow
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Sarah C Armstrong
- Department of Pediatrics, Duke University School of Medicine, Durham, North Carolina, USA
| | - Patrick C Seed
- Division of Pediatric Infectious Diseases, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, USA
| | - John F Rawls
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
- Center for Genomic and Computational Biology, Duke University, Durham, North Carolina, USA
| | - Lawrence A David
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, USA
- Program in Computational Biology and Bioinformatics, Duke University, Durham, North Carolina, USA
- Center for Genomic and Computational Biology, Duke University, Durham, North Carolina, USA
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Intestinal gases: influence on gut disorders and the role of dietary manipulations. Nat Rev Gastroenterol Hepatol 2019; 16:733-747. [PMID: 31520080 DOI: 10.1038/s41575-019-0193-z] [Citation(s) in RCA: 99] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/29/2019] [Indexed: 02/06/2023]
Abstract
The inner workings of the intestines, in which the body and microbiome intersect to influence gut function and systemic health, remain elusive. Carbon dioxide, hydrogen, methane and hydrogen sulfide, as well as a variety of trace gases, are generated by the chemical interactions and microbiota within the gut. Profiling of these intestinal gases and their responses to dietary changes can reveal the products and functions of the gut microbiota and their influence on human health. Indeed, different tools for measuring these intestinal gases have been developed, including newly developed gas-sensing capsule technology. Gases can, according to their type, concentration and volume, induce or relieve abdominal symptoms, and might also have physiological, pathogenic and therapeutic effects. Thus, profiling and modulating intestinal gases could be powerful tools for disease prevention and/or therapy. As the interactions between the microbiota, chemical constituents and fermentative substrates of the gut are principally influenced by dietary intake, altering the diet, which, in turn, changes gas profiles, is the main therapeutic approach for gastrointestinal disorders. An improved understanding of the complex interactions within the intestines that generate gases will enhance our ability to prevent, diagnose, treat and monitor many gastrointestinal disorders.
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Abstract
Carbon dioxide (CO2) is an important sensory cue for many animals, including both parasitic and free-living nematodes. Many nematodes show context-dependent, experience-dependent and/or life-stage-dependent behavioural responses to CO2, suggesting that CO2 plays crucial roles throughout the nematode life cycle in multiple ethological contexts. Nematodes also show a wide range of physiological responses to CO2. Here, we review the diverse responses of parasitic and free-living nematodes to CO2. We also discuss the molecular, cellular and neural circuit mechanisms that mediate CO2 detection in nematodes, and that drive context-dependent and experience-dependent responses of nematodes to CO2.
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7
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Metabolism, bioenergetics and thermal physiology: influences of the human intestinal microbiota. Nutr Res Rev 2019; 32:205-217. [PMID: 31258100 DOI: 10.1017/s0954422419000076] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The micro-organisms which inhabit the human gut (i.e. the intestinal microbiota) influence numerous human biochemical pathways and physiological functions. The present review focuses on two questions, 'Are intestinal microbiota effects measurable and meaningful?' and 'What research methods and variables are influenced by intestinal microbiota effects?'. These questions are considered with respect to doubly labelled water measurements of energy expenditure, heat balance calculations and models, measurements of RMR via indirect calorimetry, and diet-induced energy expenditure. Several lines of evidence suggest that the intestinal microbiota introduces measurement variability and measurement errors which have been overlooked in research studies involving nutrition, bioenergetics, physiology and temperature regulation. Therefore, we recommend that present conceptual models and research techniques be updated via future experiments, to account for the metabolic processes and regulatory influences of the intestinal microbiota.
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Bryant AS, Hallem EA. Terror in the dirt: Sensory determinants of host seeking in soil-transmitted mammalian-parasitic nematodes. Int J Parasitol Drugs Drug Resist 2018; 8:496-510. [PMID: 30396862 PMCID: PMC6287541 DOI: 10.1016/j.ijpddr.2018.10.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 10/22/2018] [Accepted: 10/24/2018] [Indexed: 12/12/2022]
Abstract
Infection with gastrointestinal parasitic nematodes is a major cause of chronic morbidity and economic burden around the world, particularly in low-resource settings. Some parasitic nematode species, including the human-parasitic threadworm Strongyloides stercoralis and human-parasitic hookworms in the genera Ancylostoma and Necator, feature a soil-dwelling infective larval stage that seeks out hosts for infection using a variety of host-emitted sensory cues. Here, we review our current understanding of the behavioral responses of soil-dwelling infective larvae to host-emitted sensory cues, and the molecular and cellular mechanisms that mediate these responses. We also discuss the development of methods for transgenesis and CRISPR/Cas9-mediated targeted mutagenesis in Strongyloides stercoralis and the closely related rat parasite Strongyloides ratti. These methods have established S. stercoralis and S. ratti as genetic model systems for gastrointestinal parasitic nematodes and are enabling more detailed investigations into the neural mechanisms that underlie the sensory-driven behaviors of this medically and economically important class of parasites.
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Affiliation(s)
- Astra S Bryant
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA, 90095, USA
| | - Elissa A Hallem
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA, 90095, USA.
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Berean KJ, Ha N, Ou JZ, Chrimes AF, Grando D, Yao CK, Muir JG, Ward SA, Burgell RE, Gibson PR, Kalantar-Zadeh K. The safety and sensitivity of a telemetric capsule to monitor gastrointestinal hydrogen production in vivo in healthy subjects: a pilot trial comparison to concurrent breath analysis. Aliment Pharmacol Ther 2018; 48:646-654. [PMID: 30067289 DOI: 10.1111/apt.14923] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 05/07/2018] [Accepted: 07/06/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND Intestinal gases are currently used for the diagnosis of disorders including small intestinal bacterial overgrowth and carbohydrate malabsorption. AIM To compare the performance of measuring hydrogen production within the gut directly with the telemetric gas-sensing capsule with that of indirect measurement through breath testing. METHODS Using standard breath testing protocols, the capsules and breath tests were simultaneously evaluated in a single-blinded trial in 12 healthy subjects. Eight received a single dose of 1.25-40 g inulin and four 20 or 40 g glucose. Safety and reliability of the capsules were also assessed. RESULTS There were no reported adverse events. All capsules were retrieved and operated without failure. Capsule measurements were in agreement with breath test measurements in magnitude but not in timing; minimal hydrogen production was observed after glucose ingestion and capsule measurements correlated with breath hydrogen after ingestion of 40 g inulin. A dose-dependent increase in concentration of hydrogen was observed from the capsule following ingestion of inulin as low as 1.25 g compared with >10 g for breath measurements. Specifically, the capsule measured >3000 times higher concentrations of hydrogen compared to breath tests, resulting in a signal-to-noise ratio of 23.4 for the capsule compared to 4.2 for the breath test. CONCLUSIONS The capsule showed high sensitivity and signal-to-noise ratio in measuring luminal hydrogen concentrations, provided information on the site of intestinal gas production, and demonstrated safety and reliability. The capsule has potential for improving diagnostic precision for disorders such as small intestinal bacterial overgrowth.
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Affiliation(s)
- Kyle J Berean
- School of Engineering, RMIT University, Melbourne, Victoria, Australia
| | - Nam Ha
- School of Engineering, RMIT University, Melbourne, Victoria, Australia
| | - Jian Zhen Ou
- School of Engineering, RMIT University, Melbourne, Victoria, Australia
| | - Adam F Chrimes
- School of Engineering, RMIT University, Melbourne, Victoria, Australia
| | - Danilla Grando
- School of Science, RMIT University, Bundoora, Victoria, Australia
| | - Chu K Yao
- Department of Gastroenterology, Alfred Health and Monash University, Melbourne, Victoria, Australia
| | - Jane G Muir
- Department of Gastroenterology, Alfred Health and Monash University, Melbourne, Victoria, Australia
| | - Stephanie A Ward
- Monash School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| | - Rebecca E Burgell
- Department of Gastroenterology, Alfred Health and Monash University, Melbourne, Victoria, Australia
| | - Peter R Gibson
- Department of Gastroenterology, Alfred Health and Monash University, Melbourne, Victoria, Australia
| | - Kourosh Kalantar-Zadeh
- School of Engineering, RMIT University, Melbourne, Victoria, Australia.,School of Chemical Engineering, University of New South Wales (UNSW), Kensington, Victoria, Australia
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Yao CK, Rotbart A, Ou JZ, Kalantar-Zadeh K, Muir JG, Gibson PR. Modulation of colonic hydrogen sulfide production by diet and mesalazine utilizing a novel gas-profiling technology. Gut Microbes 2018; 9:510-522. [PMID: 29561196 PMCID: PMC6287689 DOI: 10.1080/19490976.2018.1451280] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Excessive hydrogen sulfide (H2S) production from gut microbial metabolism may have clinically important relevance in the pathogenesis of gut disorders, including ulcerative colitis. However, little is known regarding factors that alter its production. Using a newly-designed in vitro gas-profiling technology, the study aimed to verify real-time H2S measurement reproducibility and thereafter, assess its production following exposure to dietary factors and 5-aminosalicylate acid (5-ASA). Measurements of H2S, carbon dioxide, hydrogen and methane measurements were compared between gas-profiling systems. Homogenized slurries were prepared from freshly-passed healthy human feces. Fifty ml slurries were aliquoted into separate fermentation chambers and substrates added including 1 g highly fermentable fructo-oligosaccharides (FOS) or resistant starch Hi-Maize (RS), or minimally fermentable psyllium or sterculia, 1 g cysteine, 0.9 g sodium sulfate or 1.2 mL of 1 M 5-ASA alone or in combinations. H2S release was sampled every 5 mins over 4-h and expressed relative to unspiked controls. RS suppressed H2S production by a mean 89.0 (SEM 4.8)% and FOS by 82.2 (6.2)% compared to <35 (17)% by psyllium and sterculia (p<0.001, two-way ANOVA). Cysteine stimulated H2S production by 1557 (532)%. The addition of FOS to slurries containing cysteine significantly suppressed H2S by 90 (2)% over the addition of 5-ASA (0.3 (2)%, p<0.001). Sulfate and 5-ASA had minimal overall effects. In conclusion, the H2S-profiling technology is a reproducible tool. Production of H2S is greatly enhanced by sulfur-amino acids but not inorganic sulfate, and is effectively suppressed by readily fermentable fibers. These findings inform potential designs of dietary therapies to reduce H2S production in vivo.
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Affiliation(s)
- Chu K. Yao
- Department of Gastroenterology, Central Clinical School, Alfred Centre, Monash University & Alfred Health, Melbourne, Australia,CONTACT Dr. Chu K. Yao Department of Gastroenterology, Central Clinical School, Monash University, Level 6, The Alfred Centre, 99 Commercial Road, Melbourne VIC 3004
| | - Asaf Rotbart
- School of Engineering, RMIT University, Melbourne, Australia
| | - Jian Z. Ou
- School of Engineering, RMIT University, Melbourne, Australia
| | | | - Jane G. Muir
- Department of Gastroenterology, Central Clinical School, Alfred Centre, Monash University & Alfred Health, Melbourne, Australia
| | - Peter R. Gibson
- Department of Gastroenterology, Central Clinical School, Alfred Centre, Monash University & Alfred Health, Melbourne, Australia
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A human pilot trial of ingestible electronic capsules capable of sensing different gases in the gut. NATURE ELECTRONICS 2018. [DOI: 10.1038/s41928-017-0004-x] [Citation(s) in RCA: 151] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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12
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Rotbart A, Moate PJ, Yao CK, Ou JZ, Kalantar-Zadeh K. A novel mathematical model for the dynamic assessment of gas composition and production in closed or vented fermentation systems. SENSORS AND ACTUATORS B-CHEMICAL 2018. [DOI: 10.1016/j.snb.2017.07.066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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