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McCallum G, Tropini C. The gut microbiota and its biogeography. Nat Rev Microbiol 2024; 22:105-118. [PMID: 37740073 DOI: 10.1038/s41579-023-00969-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/23/2023] [Indexed: 09/24/2023]
Abstract
Biogeography is the study of species distribution and diversity within an ecosystem and is at the core of how we understand ecosystem dynamics and interactions at the macroscale. In gut microbial communities, a historical reliance on bulk sequencing to probe community composition and dynamics has overlooked critical processes whereby microscale interactions affect systems-level microbiota function and the relationship with the host. In recent years, higher-resolution sequencing and novel single-cell level data have uncovered an incredible heterogeneity in microbial composition and have enabled a more nuanced spatial understanding of the gut microbiota. In an era when spatial transcriptomics and single-cell imaging and analysis have become key tools in mammalian cell and tissue biology, many of these techniques are now being applied to the microbiota. This fresh approach to intestinal biogeography has given important insights that span temporal and spatial scales, from the discovery of mucus encapsulation of the microbiota to the quantification of bacterial species throughout the gut. In this Review, we highlight emerging knowledge surrounding gut biogeography enabled by the observation and quantification of heterogeneity across multiple scales.
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Affiliation(s)
- Giselle McCallum
- Department of Biology, Concordia University, Montreal, Quebec, Canada
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Carolina Tropini
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada.
- School of Biomedical Engineering, University of British Columbia, Vancouver, British Columbia, Canada.
- Humans and the Microbiome Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Ontario, Canada.
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Sands C, Hedin KA, Vazquez-Uribe R, Sommer MOA. Saccharomyces boulardii promoters for control of gene expression in vivo. Microb Cell Fact 2024; 23:16. [PMID: 38185666 PMCID: PMC10771652 DOI: 10.1186/s12934-023-02288-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 12/26/2023] [Indexed: 01/09/2024] Open
Abstract
BACKGROUND Interest in the use of engineered microbes to deliver therapeutic activities has increased in recent years. The probiotic yeast Saccharomyces boulardii has been investigated for production of therapeutics in the gastrointestinal tract. Well-characterised promoters are a prerequisite for robust therapeutic expression in the gut; however, S. boulardii promoters have not yet been thoroughly characterised in vitro and in vivo. RESULTS We present a thorough characterisation of the expression activities of 12 S. boulardii promoters in vitro in glucose, fructose, sucrose, inulin and acetate, under both aerobic and anaerobic conditions, as well as in the murine gastrointestinal tract. Green fluorescent protein was used to report on promoter activity. Promoter expression was found to be carbon-source dependent, with inulin emerging as a favourable carbon source. Furthermore, relative promoter expression in vivo was highly correlated with expression in sucrose (R = 0.99). CONCLUSIONS These findings provide insights into S. boulardii promoter activity and aid in promoter selection in future studies utilising S. boulardii to produce therapeutics in the gut.
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Affiliation(s)
- Carmen Sands
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Kgs. Lyngby, Denmark
| | - Karl Alex Hedin
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Kgs. Lyngby, Denmark
| | - Ruben Vazquez-Uribe
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Kgs. Lyngby, Denmark.
| | - Morten Otto Alexander Sommer
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Kgs. Lyngby, Denmark.
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Iannone V, Babu AF, Lok J, Gómez-Gallego C, D'Auria G, Vazquez-Uribe R, Vaaben TH, Bongers M, Mikkonen S, Vaittinen M, Tikkanen I, Kettunen M, Klåvus A, Sehgal R, Kaminska D, Pihlajamaki J, Hanhineva K, El-Nezami H, Sommer MOA, Kolehmainen M. Changes in liver metabolic pathways demonstrate efficacy of the combined dietary and microbial therapeutic intervention in MASLD mouse model. Mol Metab 2023; 78:101823. [PMID: 37839774 PMCID: PMC10618820 DOI: 10.1016/j.molmet.2023.101823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 10/09/2023] [Accepted: 10/09/2023] [Indexed: 10/17/2023] Open
Abstract
OBJECTIVE Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), is the most prevalent liver disease globally, yet no therapies are approved. The effects of Escherichia coli Nissle 1917 expressing aldafermin, an engineered analog of the intestinal hormone FGF19, in combination with dietary change were investigated as a potential treatment for MASLD. METHODS MASLD was induced in C57BL/6J male mice by American lifestyle-induced obesity syndrome diet and then switched to a standard chow diet for seven weeks. In addition to the dietary change, the intervention group received genetically engineered E. coli Nissle expressing aldafermin, while control groups received either E. coli Nissle vehicle or no treatment. MASLD-related plasma biomarkers were measured using an automated clinical chemistry analyzer. The liver steatosis was assessed by histology and bioimaging analysis using Fiji (ImageJ) software. The effects of the intervention in the liver were also evaluated by RNA sequencing and liquid-chromatography-based non-targeted metabolomics analysis. Pathway enrichment studies were conducted by integrating the differentially expressed genes from the transcriptomics findings with the metabolites from the metabolomics results using Ingenuity pathway analysis. RESULTS After the intervention, E. coli Nissle expressing aldafermin along with dietary changes reduced body weight, liver steatosis, plasma aspartate aminotransferase, and plasma cholesterol levels compared to the two control groups. The integration of transcriptomics with non-targeted metabolomics analysis revealed the downregulation of amino acid metabolism and related receptor signaling pathways potentially implicated in the reduction of hepatic steatosis and insulin resistance. Moreover, the downregulation of pathways linked to lipid metabolism and changes in amino acid-related pathways suggested an overall reduction of oxidative stress in the liver. CONCLUSIONS These data support the potential for using engineered microbial therapeutics in combination with dietary changes for managing MASLD.
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Affiliation(s)
- Valeria Iannone
- School of Medicine, Institute of Public Health and Clinical Nutrition, University of Eastern Finland, 70200 Kuopio, Finland
| | - Ambrin Farizah Babu
- School of Medicine, Institute of Public Health and Clinical Nutrition, University of Eastern Finland, 70200 Kuopio, Finland; Afekta Technologies Ltd., Microkatu 1, 70210 Kuopio, Finland
| | - Johnson Lok
- School of Medicine, Institute of Public Health and Clinical Nutrition, University of Eastern Finland, 70200 Kuopio, Finland
| | - Carlos Gómez-Gallego
- School of Medicine, Institute of Public Health and Clinical Nutrition, University of Eastern Finland, 70200 Kuopio, Finland.
| | - Giuseppe D'Auria
- Sequencing and Bioinformatics Service, Foundation for the Promotion of Health and Biomedical Research of Valencia Region, FISABIO, 46020 Valencia, Spain; CIBER in Epidemiology and Public Health (CIBERESP), Instituto de Salud Carlos III, 28029, Madrid, Spain
| | - Ruben Vazquez-Uribe
- Technical University of Denmark, The Novo Nordisk Foundation Center for Biosustainability, 2800 Kongens Lyngby, Denmark
| | - Troels Holger Vaaben
- Technical University of Denmark, The Novo Nordisk Foundation Center for Biosustainability, 2800 Kongens Lyngby, Denmark
| | - Mareike Bongers
- Technical University of Denmark, The Novo Nordisk Foundation Center for Biosustainability, 2800 Kongens Lyngby, Denmark
| | - Santtu Mikkonen
- University Department of Technical Physics, University of Eastern Finland, 70211 Kuopio, Finland
| | - Maija Vaittinen
- School of Medicine, Institute of Public Health and Clinical Nutrition, University of Eastern Finland, 70200 Kuopio, Finland
| | - Ida Tikkanen
- School of Medicine, Institute of Public Health and Clinical Nutrition, University of Eastern Finland, 70200 Kuopio, Finland
| | - Mikko Kettunen
- Biomedical Imaging Unit, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211, Kuopio, Finland
| | - Anton Klåvus
- Afekta Technologies Ltd., Microkatu 1, 70210 Kuopio, Finland
| | - Ratika Sehgal
- School of Medicine, Institute of Public Health and Clinical Nutrition, University of Eastern Finland, 70200 Kuopio, Finland
| | - Dorota Kaminska
- School of Medicine, Institute of Public Health and Clinical Nutrition, University of Eastern Finland, 70200 Kuopio, Finland; Department of Medicine, Division of Cardiology, University of California, Los Angeles, CA 90095, USA
| | - Jussi Pihlajamaki
- School of Medicine, Institute of Public Health and Clinical Nutrition, University of Eastern Finland, 70200 Kuopio, Finland; Department of Medicine, Endocrinology and Clinical Nutrition, Kuopio University Hospital, 70210 Kuopio, Finland
| | - Kati Hanhineva
- School of Medicine, Institute of Public Health and Clinical Nutrition, University of Eastern Finland, 70200 Kuopio, Finland; Afekta Technologies Ltd., Microkatu 1, 70210 Kuopio, Finland; Department of Life Technologies, Food Sciences Unit, University of Turku, 20014 Turku, Finland
| | - Hani El-Nezami
- School of Medicine, Institute of Public Health and Clinical Nutrition, University of Eastern Finland, 70200 Kuopio, Finland; University of Hong Kong, Hong Kong SAR, Molecular and Cell Biology Research Area, School of Biological Sciences, Hong Kong, Hong Kong, China
| | - Morten Otto Alexander Sommer
- Technical University of Denmark, The Novo Nordisk Foundation Center for Biosustainability, 2800 Kongens Lyngby, Denmark.
| | - Marjukka Kolehmainen
- School of Medicine, Institute of Public Health and Clinical Nutrition, University of Eastern Finland, 70200 Kuopio, Finland
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Tumas S, Meldgaard TS, Vaaben TH, Suarez Hernandez S, Rasmussen AT, Vazquez-Uribe R, Hadrup SR, Sommer MOA. Engineered E. coli Nissle 1917 for delivery of bioactive IL-2 for cancer immunotherapy. Sci Rep 2023; 13:12506. [PMID: 37532747 PMCID: PMC10397246 DOI: 10.1038/s41598-023-39365-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 07/24/2023] [Indexed: 08/04/2023] Open
Abstract
In this study we performed a step-wise optimization of biologically active IL-2 for delivery using E. coli Nissle 1917. Engineering of the strain was coupled with an in vitro cell assay to measure the biological activity of microbially produced IL-2 (mi-IL2). Next, we assessed the immune modulatory potential of mi-IL2 using a 3D tumor spheroid model demonstrating a strong effect on immune cell activation. Finally, we evaluated the anticancer properties of the engineered strain in a murine CT26 tumor model. The engineered strain was injected intravenously and selectively colonized tumors. The treatment was well-tolerated, and tumors of treated mice showed a modest reduction in tumor growth rate, as well as significantly elevated levels of IL-2 in the tumor. This work demonstrates a workflow for researchers interested in engineering E. coli Nissle for a new class of microbial therapy against cancer.
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Affiliation(s)
- Sarunas Tumas
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | | | - Troels Holger Vaaben
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | | | | | - Ruben Vazquez-Uribe
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Sine Reker Hadrup
- Department of Health Technology, Technical University of Denmark, Lyngby, Denmark
| | - Morten O A Sommer
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark.
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van ‘t Hof M, Mohite OS, Monk JM, Weber T, Palsson BO, Sommer MOA. High-quality genome-scale metabolic network reconstruction of probiotic bacterium Escherichia coli Nissle 1917. BMC Bioinformatics 2022; 23:566. [PMID: 36585633 PMCID: PMC9801561 DOI: 10.1186/s12859-022-05108-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 12/12/2022] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Escherichia coli Nissle 1917 (EcN) is a probiotic bacterium used to treat various gastrointestinal diseases. EcN is increasingly being used as a chassis for the engineering of advanced microbiome therapeutics. To aid in future engineering efforts, our aim was to construct an updated metabolic model of EcN with extended secondary metabolite representation. RESULTS An updated high-quality genome-scale metabolic model of EcN, iHM1533, was developed based on comparison with 55 E. coli/Shigella reference GEMs and manual curation, including expanded secondary metabolite pathways (enterobactin, salmochelins, aerobactin, yersiniabactin, and colibactin). The model was validated and improved using phenotype microarray data, resulting in an 82.3% accuracy in predicting growth phenotypes on various nutrition sources. Flux variability analysis with previously published 13C fluxomics data validated prediction of the internal central carbon fluxes. A standardised test suite called Memote assessed the quality of iHM1533 to have an overall score of 89%. The model was applied by using constraint-based flux analysis to predict targets for optimisation of secondary metabolite production. Modelling predicted design targets from across amino acid metabolism, carbon metabolism, and other subsystems that are common or unique for influencing the production of various secondary metabolites. CONCLUSION iHM1533 represents a well-annotated metabolic model of EcN with extended secondary metabolite representation. Phenotype characterisation and the iHM1533 model provide a better understanding of the metabolic capabilities of EcN and will help future metabolic engineering efforts.
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Affiliation(s)
- Max van ‘t Hof
- grid.5170.30000 0001 2181 8870The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Omkar S. Mohite
- grid.5170.30000 0001 2181 8870The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Jonathan M. Monk
- grid.266100.30000 0001 2107 4242Department of Bioengineering, University of California San Diego, La Jolla, CA 92093 USA
| | - Tilmann Weber
- grid.5170.30000 0001 2181 8870The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Bernhard O. Palsson
- grid.5170.30000 0001 2181 8870The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kongens Lyngby, Denmark ,grid.266100.30000 0001 2107 4242Department of Bioengineering, University of California San Diego, La Jolla, CA 92093 USA
| | - Morten O. A. Sommer
- grid.5170.30000 0001 2181 8870The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
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Abstract
The engineering of microbial cells to produce and secrete therapeutics directly in the human body, known as advanced microbial therapeutics, is an exciting alternative to current drug delivery routes. These living therapeutics can be engineered to sense disease biomarkers and, in response, deliver a therapeutic activity. This strategy allows for precise and self-regulating delivery of a therapeutic that adapts to the disease state of the individual patient. Numerous sensing systems have been characterized for use in prokaryotes, but a very limited number of advanced microbial therapeutics have incorporated such sensors. We characterized eight different sensors that respond to physiologically relevant conditions and molecules found in the human body in the probiotic strain Escherichia coli Nissle 1917. The resulting sensors were characterized under aerobic and anaerobic conditions and were demonstrated to be functional under gut-like conditions using the nematode Caenorhabditis elegans as an in vivo model. We show for the first time how a biosensor is able to detect in vivo the bile acid-like molecule Δ4-dafachronic acid, a small molecule in C. elegans that regulates lifespan. Furthermore, we exemplify how bacterial sensors can be used to dynamically report on changes in the intestinal environment of C. elegans, by demonstrating the use of a biosensor able to detect changes in lactate concentrations in the gut lumen of individual C. elegans. The biosensors presented in this study allow for dynamic control of expression in vivo and represent a valuable tool in further developing advanced microbiome therapeutics.
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Kydd L, Shiveshwarkar P, Jaworski J. Engineering Escherichia coli for Conversion of Dietary Isoflavones in the Gut. ACS Synth Biol 2022; 11:3575-3582. [PMID: 36282591 DOI: 10.1021/acssynbio.2c00277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Introducing metabolic pathways to the gut is important to tailor the biochemical components ultimately absorbed by the host. Given identical diets, hosts possessing different consortia of gut bacteria can exhibit distinct health outcomes regulated by metabolic capabilities of the gut microbiota. The disparate competency of the population to metabolize isoflavones, such as dietary daidzein, has shown health benefits for those individuals possessing gut bacteria capable of producing equol from daidzein-rich diets. To begin addressing health inequalities due to gut metabolic pathway deficiencies, we developed a probiotic that allows metabolism of isoflavones to provide a gut phenotype paralleling that of natural equol producers. Toward this goal, we engineered Escherichia coli to produce the enzymes necessary for conversion of daidzein to equol, and as demonstrated in a murine model, these bacteria enabled elevated serum equol levels to dietary daidzein, thus serving as a starting point for more sophisticated systems.
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Affiliation(s)
- LeNaiya Kydd
- Department of Bioengineering, University of Texas at Arlington, Arlington, Texas 76010, United States
| | - Priyanka Shiveshwarkar
- Department of Bioengineering, University of Texas at Arlington, Arlington, Texas 76010, United States
| | - Justyn Jaworski
- Department of Bioengineering, University of Texas at Arlington, Arlington, Texas 76010, United States
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Bayer C, Sepulchro AGV, Rennig M, Nørholm MH. Efficient Bacterial Genome Engineering throughout the Central Dogma Using the Dual-Selection Marker tetAOPT. ACS Synth Biol 2022; 11:3440-3450. [PMID: 36206506 PMCID: PMC9594774 DOI: 10.1021/acssynbio.2c00345] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Engineering of bacterial genomes is a fundamental craft in contemporary biotechnology. The ability to precisely edit chromosomes allows for the development of cells with specific phenotypes for metabolic engineering and for the creation of minimized genomes. Genetic tools are needed to select for cells that underwent editing, and dual-selection markers that enable both positive and negative selection are highly useful. Here, we present an optimized and easy-to-use version of the tetA dual-selection marker and demonstrate how this tetAOPT can be used efficiently to engineer at different stages of the central dogma of molecular biology. On the DNA level, tetAOPT can be used to create scarless knockouts across the Escherichia coli genome with efficiency above 90%, whereas recombinant gene integrations can be achieved with approximately 50% efficiency. On the RNA and protein level, we show that tetAOPT enables advanced genome engineering of both gene translation and transcription by introducing sequence variation in the translation initiation region or by exchanging promoters. Finally, we demonstrate the use of tetAOPT for genome engineering in the industrially relevant probiotic strain E. coli Nissle.
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Robinson CM, Short NE, Riglar DT. Achieving spatially precise diagnosis and therapy in the mammalian gut using synthetic microbial gene circuits. Front Bioeng Biotechnol 2022; 10:959441. [PMID: 36118573 PMCID: PMC9478464 DOI: 10.3389/fbioe.2022.959441] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 08/08/2022] [Indexed: 11/13/2022] Open
Abstract
The mammalian gut and its microbiome form a temporally dynamic and spatially heterogeneous environment. The inaccessibility of the gut and the spatially restricted nature of many gut diseases translate into difficulties in diagnosis and therapy for which novel tools are needed. Engineered bacterial whole-cell biosensors and therapeutics have shown early promise at addressing these challenges. Natural and engineered sensing systems can be repurposed in synthetic genetic circuits to detect spatially specific biomarkers during health and disease. Heat, light, and magnetic signals can also activate gene circuit function with externally directed spatial precision. The resulting engineered bacteria can report on conditions in situ within the complex gut environment or produce biotherapeutics that specifically target host or microbiome activity. Here, we review the current approaches to engineering spatial precision for in vivo bacterial diagnostics and therapeutics using synthetic circuits, and the challenges and opportunities this technology presents.
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