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Ruiz-Perez D, Gimon I, Sazal M, Mathee K, Narasimhan G. Unfolding and de-confounding: biologically meaningful causal inference from longitudinal multi-omic networks using METALICA. mSystems 2024:e0130323. [PMID: 39240096 DOI: 10.1128/msystems.01303-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 07/10/2024] [Indexed: 09/07/2024] Open
Abstract
A key challenge in the analysis of microbiome data is the integration of multi-omic datasets and the discovery of interactions between microbial taxa, their expressed genes, and the metabolites they consume and/or produce. In an effort to improve the state of the art in inferring biologically meaningful multi-omic interactions, we sought to address some of the most fundamental issues in causal inference from longitudinal multi-omics microbiome data sets. We developed METALICA, a suite of tools and techniques that can infer interactions between microbiome entities. METALICA introduces novel unrolling and de-confounding techniques used to uncover multi-omic entities that are believed to act as confounders for some of the relationships that may be inferred using standard causal inferencing tools. The results lend support to predictions about biological models and processes by which microbial taxa interact with each other in a microbiome. The unrolling process helps identify putative intermediaries (genes and/or metabolites) to explain the interactions between microbes; the de-confounding process identifies putative common causes that may lead to spurious relationships to be inferred. METALICA was applied to the networks inferred by existing causal discovery, and network inference algorithms were applied to a multi-omics data set resulting from a longitudinal study of IBD microbiomes. The most significant unrollings and de-confoundings were manually validated using the existing literature and databases. IMPORTANCE We have developed a suite of tools and techniques capable of inferring interactions between microbiome entities. METALICA introduces novel techniques called unrolling and de-confounding that are employed to uncover multi-omic entities considered to be confounders for some of the relationships that may be inferred using standard causal inferencing tools. To evaluate our method, we conducted tests on the inflammatory bowel disease (IBD) dataset from the iHMP longitudinal study, which we pre-processed in accordance with our previous work. From this dataset, we generated various subsets, encompassing different combinations of metagenomics, metabolomics, and metatranscriptomics datasets. Using these multi-omics datasets, we demonstrate how the unrolling process aids in the identification of putative intermediaries (genes and/or metabolites) to explain the interactions between microbes. Additionally, the de-confounding process identifies potential common causes that may give rise to spurious relationships to be inferred. The most significant unrollings and de-confoundings were manually validated using the existing literature and databases.
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Affiliation(s)
- Daniel Ruiz-Perez
- Bioinformatics Research Group (BioRG), Florida International University, Miami, Florida, USA
| | - Isabella Gimon
- Bioinformatics Research Group (BioRG), Florida International University, Miami, Florida, USA
| | - Musfiqur Sazal
- Bioinformatics Research Group (BioRG), Florida International University, Miami, Florida, USA
| | - Kalai Mathee
- Florida International University, Miami, Florida, USA
- Biomolecular Sciences Institute, Florida International University, Miami, Florida, USA
| | - Giri Narasimhan
- Bioinformatics Research Group (BioRG), Florida International University, Miami, Florida, USA
- Biomolecular Sciences Institute, Florida International University, Miami, Florida, USA
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2
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Midani FS, Danhof HA, Mathew N, Ardis CK, Garey KW, Spinler JK, Britton RA. Emerging Clostridioides difficile ribotypes have divergent metabolic phenotypes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.15.608124. [PMID: 39185189 PMCID: PMC11343193 DOI: 10.1101/2024.08.15.608124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/27/2024]
Abstract
Clostridioides difficile is a gram-positive spore-forming pathogen that commonly causes diarrheal infections in the developed world. Although C. difficile is a genetically diverse species, certain ribotypes are overrepresented in human infections. It is unknown if metabolic adaptations are essential for the emergence of these epidemic ribotypes. Here, we tested carbon substrate utilization by 88 C. difficile isolates and looked for differences in growth between 22 ribotypes. By profiling clinical isolates, we assert that C. difficile is a generalist species capable of growing on a variety of carbon substrates. Further, C. difficile strains clustered by phylogenetic relationship and displayed ribotype-specific and clade-specific metabolic capabilities. Surprisingly, we observed that two emerging lineages, ribotypes 023 and 255, have divergent metabolic phenotypes. In addition, although C. difficile Clade 5 is the most evolutionary distant clade and often detected in animals, it displayed more robust growth on simple dietary sugars than Clades 1-4. Altogether, our results corroborate the generalist metabolic strategy of C. difficile and demonstrate lineage-specific metabolic capabilities. In addition, our approach can be adapted to the study of additional pathogens to ascertain their metabolic niches in the gut. IMPORTANCE The gut pathogen Clostridioides difficile utilizes a wide range of carbon sources. Microbial communities can be rationally designed to combat C. difficile by depleting its preferred nutrients in the gut. However, C. difficile is genetically diverse with hundreds of identified ribotypes and most of its metabolic studies were performed with lab-adapted strains. Here, we profiled carbon metabolism by a myriad of C. difficile clinical isolates. While the metabolic capabilities of these isolates clustered by their genetic lineage, we observed surprising metabolic divergence between two emerging lineages. We also found that the most genetically distant clade grew robustly on simple dietary sugars, posing intriguing questions about the adaptation of C. difficile to the human gut. Altogether, our results underscore the importance of considering the metabolic diversity of pathogens in the study of their evolution and the rational design of therapeutic interventions.
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3
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Brown HA, Morris AL, Pudlo NA, Hopkins AE, Martens EC, Golob JL, Koropatkin NM. Acarbose Impairs Gut Bacteroides Growth by Targeting Intracellular GH97 Enzymes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.20.595031. [PMID: 38826241 PMCID: PMC11142093 DOI: 10.1101/2024.05.20.595031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Acarbose is a type-2 diabetes medicine that inhibits dietary starch breakdown into glucose by inhibiting host amylase and glucosidase enzymes. Numerous gut species in the Bacteroides genus enzymatically break down starch and change in relative abundance within the gut microbiome in acarbose-treated individuals. To mechanistically explain this observation, we used two model starch-degrading Bacteroides, Bacteroides ovatus (Bo) and Bacteroides thetaiotaomicron (Bt). Bt growth is severely impaired by acarbose whereas Bo growth is not. The Bacteroides use a starch utilization system (Sus) to grow on starch. We hypothesized that Bo and Bt Sus enzymes are differentially inhibited by acarbose. Instead, we discovered that although acarbose primarily targets the Sus periplasmic GH97 enzymes in both organisms, the drug affects starch processing at multiple other points. Acarbose competes for transport through the Sus beta-barrel proteins and binds to the Sus transcriptional regulators. Further, Bo expresses a non-Sus GH97 (BoGH97D) when grown in starch with acarbose. The Bt homolog, BtGH97H, is not expressed in the same conditions, nor can overexpression of BoGH97D complement the Bt growth inhibition in the presence of acarbose. This work informs us about unexpected complexities of Sus function and regulation in Bacteroides, including variation between related species. Further, this indicates that the gut microbiome may be a source of variable response to acarbose treatment for diabetes.
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Affiliation(s)
- Haley A. Brown
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Adeline L. Morris
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Nicholas A. Pudlo
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Ashley E. Hopkins
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Eric C. Martens
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Jonathan L. Golob
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
- Department of Internal Medicine, Division of Infectious Diseases, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Nicole M. Koropatkin
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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4
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McMillan AS, Foley MH, Perkins CE, Theriot CM. Loss of Bacteroides thetaiotaomicron bile acid-altering enzymes impacts bacterial fitness and the global metabolic transcriptome. Microbiol Spectr 2024; 12:e0357623. [PMID: 38018975 PMCID: PMC10783122 DOI: 10.1128/spectrum.03576-23] [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: 10/04/2023] [Accepted: 10/27/2023] [Indexed: 11/30/2023] Open
Abstract
IMPORTANCE Recent work on bile salt hydrolases (BSHs) in Gram-negative bacteria, such as Bacteroides, has primarily focused on how they can impact host physiology. However, the benefits bile acid metabolism confers to the bacterium that performs it are not well understood. In this study, we set out to define if and how Bacteroides thetaiotaomicron (B. theta) uses its BSHs and hydroxysteroid dehydrogenase to modify bile acids to provide a fitness advantage for itself in vitro and in vivo. Genes encoding bile acid-altering enzymes were able to impact how B. theta responds to nutrient limitation in the presence of bile acids, specifically carbohydrate metabolism, affecting many polysaccharide utilization loci. This suggests that B. theta may be able to shift its metabolism, specifically its ability to target different complex glycans including host mucin, when it comes into contact with specific bile acids in the gut.
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Affiliation(s)
- Arthur S. McMillan
- Department of Biological Sciences, Genetics Program, College of Science, North Carolina State University, Raleigh, North Carolina, USA
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
| | - Matthew H. Foley
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, North Carolina, USA
| | - Caroline E. Perkins
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
| | - Casey M. Theriot
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
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Xu K, Ren Y, Zhao S, Feng J, Wu Q, Gong X, Chen J, Xie P. Oral D-ribose causes depressive-like behavior by altering glycerophospholipid metabolism via the gut-brain axis. Commun Biol 2024; 7:69. [PMID: 38195757 PMCID: PMC10776610 DOI: 10.1038/s42003-023-05759-1] [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: 09/03/2023] [Accepted: 12/29/2023] [Indexed: 01/11/2024] Open
Abstract
Our previous work has shown that D-ribose (RIB)-induced depressive-like behaviors in mice. However, the relationship between variations in RIB levels and depression as well as potential RIB participation in depressive disorder is yet unknown. Here, a reanalysis of metabonomics data from depressed patients and depression model rats is performed to clarify whether the increased RIB level is positively correlated with the severity of depression. Moreover, we characterize intestinal epithelial barrier damage, gut microbial composition and function, and microbiota-gut-brain metabolic signatures in RIB-fed mice using colonic histomorphology, 16 S rRNA gene sequencing, and untargeted metabolomics analysis. The results show that RIB caused intestinal epithelial barrier impairment and microbiota-gut-brain axis dysbiosis. These microbial and metabolic modules are consistently enriched in peripheral (fecal, colon wall, and serum) and central (hippocampus) glycerophospholipid metabolism. In addition, three differential genera (Lachnospiraceae_UCG-006, Turicibacter, and Akkermansia) and two types of glycerophospholipids (phosphatidylcholine and phosphatidylethanolamine) have greater contributions to the overall correlations between differential genera and glycerophospholipids. These findings suggest that the disturbances of gut microbiota by RIB may contribute to the onset of depressive-like behaviors via regulating glycerophospholipid metabolism, and providing new insight for understanding the function of microbiota-gut-brain axis in depression.
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Affiliation(s)
- Ke Xu
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, 400016, Chongqing, China
- National Health Commission Key Laboratory of Diagnosis and Treatment on Brain Functional Diseases, The First Affiliated Hospital of Chongqing Medical University, 400016, Chongqing, China
| | - Yi Ren
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, 400016, Chongqing, China
- National Health Commission Key Laboratory of Diagnosis and Treatment on Brain Functional Diseases, The First Affiliated Hospital of Chongqing Medical University, 400016, Chongqing, China
| | - Shuang Zhao
- Department of Infectious Diseases, Key Laboratory of Molecular Biology for Infectious Diseases, Ministry of Education, Institute for Viral Hepatitis, The Second Affiliated Hospital of Chongqing Medical University, 400010, Chongqing, China
- Lab of Stem Cell and Tissue Engineering, Department of Histology and Embryology, 400016, Chongqing, China
| | - Jinzhou Feng
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, 400016, Chongqing, China
| | - Qingyuan Wu
- National Health Commission Key Laboratory of Diagnosis and Treatment on Brain Functional Diseases, The First Affiliated Hospital of Chongqing Medical University, 400016, Chongqing, China
- Department of Neurology, Chongqing University Three Gorges Hospital, 404031, Chongqing, China
| | - Xue Gong
- National Health Commission Key Laboratory of Diagnosis and Treatment on Brain Functional Diseases, The First Affiliated Hospital of Chongqing Medical University, 400016, Chongqing, China
| | - Jianjun Chen
- Institute of Life Sciences, Chongqing Medical University, 400016, Chongqing, China.
| | - Peng Xie
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, 400016, Chongqing, China.
- National Health Commission Key Laboratory of Diagnosis and Treatment on Brain Functional Diseases, The First Affiliated Hospital of Chongqing Medical University, 400016, Chongqing, China.
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6
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Kijner S, Ennis D, Shmorak S, Florentin A, Yassour M. CRISPR-Cas-based identification of a sialylated human milk oligosaccharides utilization cluster in the infant gut commensal Bacteroides dorei. Nat Commun 2024; 15:105. [PMID: 38167825 PMCID: PMC10761964 DOI: 10.1038/s41467-023-44437-y] [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: 04/24/2023] [Accepted: 12/13/2023] [Indexed: 01/05/2024] Open
Abstract
The infant gut microbiome is impacted by early-life feeding, as human milk oligosaccharides (HMOs) found in breastmilk cannot be digested by infants and serve as nutrients for their gut bacteria. While the vast majority of HMO-utilization research has focused on Bifidobacterium species, recent studies have suggested additional HMO-utilizers, mostly Bacteroides, yet their utilization mechanism is poorly characterized. Here, we investigate Bacteroides dorei isolates from breastfed-infants and identify that polysaccharide utilization locus (PUL) 33 enables B. dorei to utilize sialylated HMOs. We perform transcriptional profiling and identity upregulated genes when growing on sialylated HMOs. Using CRISPR-Cas12 to knock-out four PUL33 genes, combined with complementation assays, we identify GH33 as the critical gene in PUL33 for sialylated HMO-utilization. This demonstration of an HMO-utilization system by Bacteroides species isolated from infants opens the way to further characterization of additional such systems, to better understand HMO-utilization in the infant gut.
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Affiliation(s)
- Sivan Kijner
- Microbiology & Molecular Genetics Department, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Dena Ennis
- Microbiology & Molecular Genetics Department, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Shimrit Shmorak
- Microbiology & Molecular Genetics Department, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Anat Florentin
- Microbiology & Molecular Genetics Department, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
- The Kuvin Center for the Study of Infectious and Tropical Diseases, Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Moran Yassour
- Microbiology & Molecular Genetics Department, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel.
- The Rachel and Selim Benin School of Computer Science and Engineering, The Hebrew University of Jerusalem, Jerusalem, Israel.
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Ruiz-Perez D, Gimon I, Sazal M, Mathee K, Narasimhan G. Unfolding and De-confounding: Biologically meaningful causal inference from longitudinal multi-omic networks using METALICA. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.12.571384. [PMID: 38168315 PMCID: PMC10760167 DOI: 10.1101/2023.12.12.571384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
A key challenge in the analysis of microbiome data is the integration of multi-omic datasets and the discovery of interactions between microbial taxa, their expressed genes, and the metabolites they consume and/or produce. In an effort to improve the state-of-the-art in inferring biologically meaningful multi-omic interactions, we sought to address some of the most fundamental issues in causal inference from longitudinal multi-omics microbiome data sets. We developed METALICA, a suite of tools and techniques that can infer interactions between microbiome entities. METALICA introduces novel unrolling and de-confounding techniques used to uncover multi-omic entities that are believed to act as confounders for some of the relationships that may be inferred using standard causal inferencing tools. The results lend support to predictions about biological models and processes by which microbial taxa interact with each other in a microbiome. The unrolling process helps to identify putative intermediaries (genes and/or metabolites) to explain the interactions between microbes; the de-confounding process identifies putative common causes that may lead to spurious relationships to be inferred. METALICA was applied to the networks inferred by existing causal discovery and network inference algorithms applied to a multi-omics data set resulting from a longitudinal study of IBD microbiomes. The most significant unrollings and de-confoundings were manually validated using the existing literature and databases.
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Affiliation(s)
- Daniel Ruiz-Perez
- Bioinformatics Research Group (BioRG), Florida International University, Miami, FL 33199, USA
| | - Isabella Gimon
- Bioinformatics Research Group (BioRG), Florida International University, Miami, FL 33199, USA
| | - Musfiqur Sazal
- Bioinformatics Research Group (BioRG), Florida International University, Miami, FL 33199, USA
| | - Kalai Mathee
- Florida International University, Miami, FL 33199, USA
- Biomolecular Sciences Institute, Florida International University, Miami, FL 33199, USA
| | - Giri Narasimhan
- Bioinformatics Research Group (BioRG), Florida International University, Miami, FL 33199, USA
- Biomolecular Sciences Institute, Florida International University, Miami, FL 33199, USA
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8
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Groisman EA, Han W, Krypotou E. Advancing the fitness of gut commensal bacteria. Science 2023; 382:766-768. [PMID: 37972163 PMCID: PMC10838159 DOI: 10.1126/science.adh9165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
Nutrient starvation of beneficial bacteria helps them colonize the human gut.
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Affiliation(s)
- Eduardo A. Groisman
- Department of Microbial Pathogenesis, Yale School of Medicine; New Haven, CT, USA
| | - Weiwei Han
- Department of Microbial Pathogenesis, Yale School of Medicine; New Haven, CT, USA
| | - Emilia Krypotou
- Department of Microbial Pathogenesis, Yale School of Medicine; New Haven, CT, USA
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9
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Marsh JW, Kirk C, Ley RE. Toward Microbiome Engineering: Expanding the Repertoire of Genetically Tractable Members of the Human Gut Microbiome. Annu Rev Microbiol 2023; 77:427-449. [PMID: 37339736 DOI: 10.1146/annurev-micro-032421-112304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/22/2023]
Abstract
Genetic manipulation is necessary to interrogate the functions of microbes in their environments, such as the human gut microbiome. Yet, the vast majority of human gut microbiome species are not genetically tractable. Here, we review the hurdles to seizing genetic control of more species. We address the barriers preventing the application of genetic techniques to gut microbes and report on genetic systems currently under development. While methods aimed at genetically transforming many species simultaneously in situ show promise, they are unable to overcome many of the same challenges that exist for individual microbes. Unless a major conceptual breakthrough emerges, the genetic tractability of the microbiome will remain an arduous task. Increasing the list of genetically tractable organisms from the human gut remains one of the highest priorities for microbiome research and will provide the foundation for microbiome engineering.
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Affiliation(s)
- James W Marsh
- Department of Microbiome Science, Max Planck Institute for Biology, Tübingen, Germany;
| | - Christian Kirk
- Department of Microbiome Science, Max Planck Institute for Biology, Tübingen, Germany;
| | - Ruth E Ley
- Department of Microbiome Science, Max Planck Institute for Biology, Tübingen, Germany;
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10
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Engelhart MJ, Glowacki RWP, Till JM, Harding CV, Martens EC, Ahern PP. The NQR Complex Regulates the Immunomodulatory Function of Bacteroides thetaiotaomicron. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2023; 211:767-781. [PMID: 37486212 PMCID: PMC10527448 DOI: 10.4049/jimmunol.2200892] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 06/26/2023] [Indexed: 07/25/2023]
Abstract
The gut microbiome and intestinal immune system are engaged in a dynamic interplay that provides myriad benefits to host health. However, the microbiome can also elicit damaging inflammatory responses, and thus establishing harmonious immune-microbiome interactions is essential to maintain homeostasis. Gut microbes actively coordinate the induction of anti-inflammatory responses that establish these mutualistic interactions. Despite this, the microbial pathways that govern this dialogue remain poorly understood. We investigated the mechanisms through which the gut symbiont Bacteroides thetaiotaomicron exerts its immunomodulatory functions on murine- and human-derived cells. Our data reveal that B. thetaiotaomicron stimulates production of the cytokine IL-10 via secreted factors that are packaged into outer membrane vesicles, in a TLR2- and MyD88-dependent manner. Using a transposon mutagenesis-based screen, we identified a key role for the B. thetaiotaomicron-encoded NADH:ubiquinone oxidoreductase (NQR) complex, which regenerates NAD+ during respiration, in this process. Finally, we found that disruption of NQR reduces the capacity of B. thetaiotaomicron to induce IL-10 by impairing biogenesis of outer membrane vesicles. These data identify a microbial pathway with a previously unappreciated role in gut microbe-mediated immunomodulation that may be targeted to manipulate the capacity of the microbiome to shape host immunity.
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Affiliation(s)
- Morgan J. Engelhart
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Robert W. P. Glowacki
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Jessica M. Till
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Clifford V. Harding
- Department of Pathology, Case Western Reserve University/University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
| | - Eric C. Martens
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Philip P. Ahern
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
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11
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McMillan AS, Foley MH, Perkins CE, Theriot CM. Loss of Bacteroides thetaiotaomicron bile acid altering enzymes impact bacterial fitness and the global metabolic transcriptome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.27.546749. [PMID: 37425690 PMCID: PMC10327073 DOI: 10.1101/2023.06.27.546749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Bacteroides thetaiotaomicron (B. theta) is a Gram-negative gut bacterium that encodes enzymes that alter the bile acid pool in the gut. Primary bile acids are synthesized by the host liver and are modified by gut bacteria. B. theta encodes two bile salt hydrolases (BSHs), as well as a hydroxysteroid dehydrogenase (HSDH). We hypothesize that B. theta modifies the bile acid pool in the gut to provide a fitness advantage for itself. To investigate each gene's role, different combinations of genes encoding bile acid altering enzymes (bshA, bshB, and hsdhA) were knocked out by allelic exchange, including a triple KO. Bacterial growth and membrane integrity assays were done in the presence and absence of bile acids. To explore if B. theta's response to nutrient limitation changes due to the presence of bile acid altering enzymes, RNASeq analysis of WT and triple KO strains in the presence and absence of bile acids was done. WT B. theta is more sensitive to deconjugated bile acids (CA, CDCA, and DCA) compared to the triple KO, which also decreased membrane integrity. The presence of bshB is detrimental to growth in conjugated forms of CDCA and DCA. RNA-Seq analysis also showed bile acid exposure impacts multiple metabolic pathways in B. theta, but DCA significantly increases expression of many genes in carbohydrate metabolism, specifically those in polysaccharide utilization loci or PULs, in nutrient limited conditions. This study suggests that bile acids B. theta encounters in the gut may signal the bacteria to increase or decrease its utilization of carbohydrates. Further study looking at the interactions between bacteria, bile acids, and the host may inform rationally designed probiotics and diets to ameliorate inflammation and disease. Importance Recent work on BSHs in Gram-negative bacteria, such as Bacteroides, has primarily focused on how they can impact host physiology. However, the benefits bile acid metabolism confers to the bacterium that performs it is not well understood. In this study we set out to define if and how B. theta uses its BSHs and HSDH to modify bile acids to provide a fitness advantage for itself in vitro and in vivo. Genes encoding bile acid altering enzymes were able to impact how B. theta responds to nutrient limitation in the presence of bile acids, specifically carbohydrate metabolism, affecting many polysaccharide utilization loci (PULs). This suggests that B. theta may be able to shift its metabolism, specifically its ability to target different complex glycans including host mucin, when it comes into contact with specific bile acids in the gut. This work will aid in our understanding of how to rationally manipulate the bile acid pool and the microbiota to exploit carbohydrate metabolism in the context of inflammation and other GI diseases.
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Affiliation(s)
- Arthur S. McMillan
- Genetics Program, Department of Biological Sciences, College of Science
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Matthew H. Foley
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC, USA
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Caroline E. Perkins
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Casey M. Theriot
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States of America
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12
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Forwood DL, Innes DJ, Parra MC, Stark T, de Souza DP, Chaves AV, Meale SJ. Feeding an unsalable carrot total-mixed ration altered bacterial amino acid degradation in the rumen of lambs. Sci Rep 2023; 13:6942. [PMID: 37117259 PMCID: PMC10147942 DOI: 10.1038/s41598-023-34181-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 04/25/2023] [Indexed: 04/30/2023] Open
Abstract
The objective of this study was to determine the influence of a total-mixed ration including unsalable carrots at 45% DM on the rumen microbiome; and the plasma, rumen and liver metabolomes. Carrots discarded at processing were investigated as an energy-dense substitute for barley grain in a conventional feedlot diet, and improved feed conversion efficiency by 25%. Here, rumen fluid was collected from 34 Merino lambs at slaughter (n = 16 control; n = 18 carrot) after a feeding period of 11-weeks. The V4 region of the 16S rRNA gene was sequenced to profile archaeal and bacterial microbe communities. Further, a comprehensive, targeted profile of known metabolites was constructed for blood plasma, rumen fluid and biopsied liver metabolites using a gas chromatography mass spectrometry (GC-MS) metabolomics approach. An in vitro batch culture was used to characterise ruminal fermentation including gas and methane (CH4) production. In vivo rumen microbial community structure of carrot fed lambs was dissimilar (P < 0.01; PERMANOVA), and all measures of alpha diversity were greater (P < 0.01), compared to those fed the control diet. Unclassified genera in Bacteroidales (15.9 ± 6.74% relative abundance; RA) were more abundant (P < 0.01) in the rumen fluid of carrot-fed lambs, while unclassified taxa in the Succinivibrionaceae family (11.1 ± 3.85% RA) were greater (P < 0.01) in the control. The carrot diet improved in vitro ruminal fermentation evidenced as an 8% increase (P < 0.01) in DM digestibility and a 13.8% reduction (P = 0.01) in CH4 on a mg/ g DM basis, while the control diet increased (P = 0.04) percentage of propionate within total VFA by 20%. Fourteen rumen fluid metabolites and 27 liver metabolites were influenced (P ≤ 0.05) by diet, while no effect (P ≥ 0.05) was observed in plasma metabolites. The carrot diet enriched (impact value = 0.13; P = 0.01) the tyrosine metabolism pathway (acetoacetic acid, dopamine and pyruvate), while the control diet enriched (impact value = 0.42; P ≤ 0.02) starch and sucrose metabolism (trehalose and glucose) in rumen fluid. This study demonstrated that feeding 45% DM unsalable carrots diversified bacterial communities in the rumen. These dietary changes influenced pathways of tyrosine degradation, such that previous improvements in feed conversion efficiency in lambs could be explained.
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Affiliation(s)
- Daniel L Forwood
- School of Agriculture and Food Sciences, Faculty of Science, The University of Queensland, Gatton, Australia
| | - David J Innes
- School of Agriculture and Food Sciences, Faculty of Science, The University of Queensland, Gatton, Australia
| | - Mariano C Parra
- School of Agriculture and Food Sciences, Faculty of Science, The University of Queensland, Gatton, Australia
| | - Terra Stark
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Australia
| | - David P de Souza
- Metabolomics Australia, Bio21 Institute, The University of Melbourne, Parkville, Australia
| | - Alex V Chaves
- School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, Camperdown, Australia
| | - Sarah J Meale
- School of Agriculture and Food Sciences, Faculty of Science, The University of Queensland, Gatton, Australia.
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13
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Modesto JL, Pearce VH, Townsend GE. Harnessing gut microbes for glycan detection and quantification. Nat Commun 2023; 14:275. [PMID: 36650134 PMCID: PMC9845299 DOI: 10.1038/s41467-022-35626-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 12/13/2022] [Indexed: 01/19/2023] Open
Abstract
Glycans facilitate critical biological functions and control the mammalian gut microbiota composition by supplying differentially accessible nutrients to distinct microbial subsets. Therefore, identifying unique glycan substrates that support defined microbial populations could inform therapeutic avenues to treat diseases via modulation of the gut microbiota composition and metabolism. However, examining heterogeneous glycan mixtures for individual microbial substrates is hindered by glycan structural complexity and diversity, which presents substantial challenges to glycomics approaches. Fortuitously, gut microbes encode specialized sensor proteins that recognize unique glycan structures and in-turn activate predictable, specific, and dynamic transcriptional responses. Here, we harness this microbial machinery to indicate the presence and abundance of compositionally similar, yet structurally distinct glycans, using a transcriptional reporter we develop. We implement these tools to examine glycan mixtures, isolate target molecules for downstream characterization, and quantify the recovered products. We assert that this toolkit could dramatically enhance our understanding of the mammalian intestinal environment and identify host-microbial interactions critical for human health.
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Affiliation(s)
- Jennifer L Modesto
- Department of Biochemistry & Molecular Biology, Penn State College of Medicine, Hershey, PA, 17033, USA.,Penn State Microbiome Center, The Pennsylvania State University, State College, PA, 16802, USA.,Center for Molecular Carcinogenesis and Toxicology, The Pennsylvania State University, State College, PA, 16802, USA
| | - Victoria H Pearce
- Department of Biochemistry & Molecular Biology, Penn State College of Medicine, Hershey, PA, 17033, USA.,Penn State Microbiome Center, The Pennsylvania State University, State College, PA, 16802, USA.,Center for Molecular Carcinogenesis and Toxicology, The Pennsylvania State University, State College, PA, 16802, USA
| | - Guy E Townsend
- Department of Biochemistry & Molecular Biology, Penn State College of Medicine, Hershey, PA, 17033, USA. .,Penn State Microbiome Center, The Pennsylvania State University, State College, PA, 16802, USA. .,Center for Molecular Carcinogenesis and Toxicology, The Pennsylvania State University, State College, PA, 16802, USA.
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14
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Pearce VH, Groisman EA, Townsend GE. Dietary sugars silence the master regulator of carbohydrate utilization in human gut Bacteroides species. Gut Microbes 2023; 15:2221484. [PMID: 37358144 PMCID: PMC10294740 DOI: 10.1080/19490976.2023.2221484] [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: 12/22/2022] [Accepted: 05/08/2023] [Indexed: 06/27/2023] Open
Abstract
The mammalian gut microbiota is a critical human health determinant with therapeutic potential for remediation of many diseases. The host diet is a key factor governing the gut microbiota composition by altering nutrient availability and supporting the expansion of distinct microbial populations. Diets rich in simple sugars modify the abundance of microbial subsets, enriching for microbiotas that elicit pathogenic outcomes. We previously demonstrated that diets rich in fructose and glucose can reduce the fitness and abundance of a human gut symbiont, Bacteroides thetaiotaomicron, by silencing the production of a critical intestinal colonization protein, called Roc, via its mRNA leader through an unknown mechanism. We have now determined that dietary sugars silence Roc by reducing the activity of BT4338, a master regulator of carbohydrate utilization. Here, we demonstrate that BT4338 is required for Roc synthesis, and that BT4338 activity is silenced by glucose or fructose. We show that the consequences of glucose and fructose on orthologous transcription factors are conserved across human intestinal Bacteroides species. This work identifies a molecular pathway by which a common dietary additive alters microbial gene expression in the gut that could be harnessed to modulate targeted microbial populations for future therapeutic interventions.
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Affiliation(s)
- Victoria H. Pearce
- Biochemistry & Molecular Biology, Penn State College of Medicine, Hershey, PA, USA
- Penn State Microbiome Center, Pennsylvania State University, State College, PA, USA
- Center for Molecular Carcinogenesis and Toxicology, Pennsylvania State University, State College, PA, USA
| | - Eduardo A. Groisman
- Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, USA
- Microbial Sciences Institute, Yale University, New Haven, CT, USA
| | - Guy E. Townsend
- Biochemistry & Molecular Biology, Penn State College of Medicine, Hershey, PA, USA
- Penn State Microbiome Center, Pennsylvania State University, State College, PA, USA
- Center for Molecular Carcinogenesis and Toxicology, Pennsylvania State University, State College, PA, USA
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15
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Lactobacillus supports Clostridiales to restrict gut colonization by multidrug-resistant Enterobacteriaceae. Nat Commun 2022; 13:5617. [PMID: 36153315 PMCID: PMC9509339 DOI: 10.1038/s41467-022-33313-w] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 09/09/2022] [Indexed: 11/10/2022] Open
Abstract
Infections by multidrug-resistant Enterobacteriaceae (MRE) are life-threatening to patients. The intestinal microbiome protects against MRE colonization, but antibiotics cause collateral damage to commensals and open the way to colonization and subsequent infection. Despite the significance of this problem, the specific commensals and mechanisms that restrict MRE colonization remain largely unknown. Here, by performing a multi-omic prospective study of hospitalized patients combined with mice experiments, we find that Lactobacillus is key, though not sufficient, to restrict MRE gut colonization. Lactobacillus rhamnosus and murinus increase the levels of Clostridiales bacteria, which induces a hostile environment for MRE growth through increased butyrate levels and reduced nutrient sources. This mechanism of colonization resistance, an interaction between Lactobacillus spp. and Clostridiales involving cooperation between microbiota members, is conserved in mice and patients. These results stress the importance of exploiting microbiome interactions for developing effective probiotics that prevent infections in hospitalized patients. Multidrug-resistant Enterobacteriaceae (MRE) represent a major threat for patients’ health. Here, the authors describe how cooperation between gut commensal bacteria (Lactobacillus spp. And Clostridiales) restrict MRE colonization in mice and patients
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16
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Rangarajan AA, Chia HE, Azaldegui CA, Olszewski MH, Pereira GV, Koropatkin NM, Biteen JS. Ruminococcus bromii enables the growth of proximal Bacteroides thetaiotaomicron by releasing glucose during starch degradation. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35471195 DOI: 10.1099/mic.0.001180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Complex carbohydrates shape the gut microbiota, and the collective fermentation of resistant starch by gut microbes positively affects human health through enhanced butyrate production. The keystone species Ruminococcus bromii (Rb) is a specialist in degrading resistant starch; its degradation products are used by other bacteria including Bacteroides thetaiotaomicron (Bt). We analysed the metabolic and spatial relationships between Rb and Bt during potato starch degradation and found that Bt utilizes glucose that is released from Rb upon degradation of resistant potato starch and soluble potato amylopectin. Additionally, we found that Rb produces a halo of glucose around it when grown on solid media containing potato amylopectin and that Bt cells deficient for growth on potato amylopectin (∆sus Bt) can grow within the halo. Furthermore, when these ∆sus Bt cells grow within this glucose halo, they have an elongated cell morphology. This long-cell phenotype depends on the glucose concentration in the solid media: longer Bt cells are formed at higher glucose concentrations. Together, our results indicate that starch degradation by Rb cross-feeds other bacteria in the surrounding region by releasing glucose. Our results also elucidate the adaptive morphology of Bt cells under different nutrient and physiological conditions.
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Affiliation(s)
| | - Hannah E Chia
- Program in Chemical Biology, University of Michigan, Ann Arbor, Michigan, USA
| | | | - Monica H Olszewski
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Gabriel V Pereira
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Nicole M Koropatkin
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Julie S Biteen
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA.,Program in Chemical Biology, University of Michigan, Ann Arbor, Michigan, USA
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17
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Glowacki RWP, Engelhart MJ, Ahern PP. Controlled Complexity: Optimized Systems to Study the Role of the Gut Microbiome in Host Physiology. Front Microbiol 2021; 12:735562. [PMID: 34646255 PMCID: PMC8503645 DOI: 10.3389/fmicb.2021.735562] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 08/24/2021] [Indexed: 12/26/2022] Open
Abstract
The profound impact of the gut microbiome on host health has led to a revolution in biomedical research, motivating researchers from disparate fields to define the specific molecular mechanisms that mediate host-beneficial effects. The advent of genomic technologies allied to the use of model microbiomes in gnotobiotic mouse models has transformed our understanding of intestinal microbial ecology and the impact of the microbiome on the host. However, despite incredible advances, our understanding of the host-microbiome dialogue that shapes host physiology is still in its infancy. Progress has been limited by challenges associated with developing model systems that are both tractable enough to provide key mechanistic insights while also reflecting the enormous complexity of the gut ecosystem. Simplified model microbiomes have facilitated detailed interrogation of transcriptional and metabolic functions of the microbiome but do not recapitulate the interactions seen in complex communities. Conversely, intact complex communities from mice or humans provide a more physiologically relevant community type, but can limit our ability to uncover high-resolution insights into microbiome function. Moreover, complex microbiomes from lab-derived mice or humans often do not readily imprint human-like phenotypes. Therefore, improved model microbiomes that are highly defined and tractable, but that more accurately recapitulate human microbiome-induced phenotypic variation are required to improve understanding of fundamental processes governing host-microbiome mutualism. This improved understanding will enhance the translational relevance of studies that address how the microbiome promotes host health and influences disease states. Microbial exposures in wild mice, both symbiotic and infectious in nature, have recently been established to more readily recapitulate human-like phenotypes. The development of synthetic model communities from such "wild mice" therefore represents an attractive strategy to overcome the limitations of current approaches. Advances in microbial culturing approaches that allow for the generation of large and diverse libraries of isolates, coupled to ever more affordable large-scale genomic sequencing, mean that we are now ideally positioned to develop such systems. Furthermore, the development of sophisticated in vitro systems is allowing for detailed insights into host-microbiome interactions to be obtained. Here we discuss the need to leverage such approaches and highlight key challenges that remain to be addressed.
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Affiliation(s)
- Robert W. P. Glowacki
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Morgan J. Engelhart
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
- Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH, United States
| | - Philip P. Ahern
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
- Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH, United States
- Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, OH, United States
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18
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Brown EM, Arellano-Santoyo H, Temple ER, Costliow ZA, Pichaud M, Hall AB, Liu K, Durney MA, Gu X, Plichta DR, Clish CA, Porter JA, Vlamakis H, Xavier RJ. Gut microbiome ADP-ribosyltransferases are widespread phage-encoded fitness factors. Cell Host Microbe 2021; 29:1351-1365.e11. [PMID: 34403684 DOI: 10.1016/j.chom.2021.07.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 06/23/2021] [Accepted: 07/22/2021] [Indexed: 12/13/2022]
Abstract
Bacterial ADP-ribosyltransferases (ADPRTs) have been described as toxins involved in pathogenesis through the modification of host proteins. Here, we report that ADPRTs are not pathogen restricted but widely prevalent in the human gut microbiome and often associated with phage elements. We validated their biochemical activity in a large clinical isolate collection and further examined Bxa, a highly abundant ADPRT in Bacteroides. Bxa is expressed, secreted, and enzymatically active in Bacteroides and can ADP-ribosylate non-muscle myosin II proteins. Addition of Bxa to epithelial cells remodeled the actin cytoskeleton and induced secretion of inosine. Bxa-encoding B. stercoris can use inosine as a carbon source and colonizes the gut to significantly greater numbers than a bxa-deleted strain in germ-free and altered Schaedler flora (ASF) mice. Colonization correlated with increased inosine concentrations in the feces and tissues. Altogether, our results show that ADPRTs are abundant in the microbiome and act as bacterial fitness factors.
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Affiliation(s)
- Eric M Brown
- Center for Computational and Integrative Biology, Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Hugo Arellano-Santoyo
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Novartis Institutes for Biomedical Research Inc., Cambridge, MA 02139, USA
| | - Emily R Temple
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | | | - Matthieu Pichaud
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Novartis Institutes for Biomedical Research Inc., Cambridge, MA 02139, USA
| | - A Brantley Hall
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Kai Liu
- Center for Computational and Integrative Biology, Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | | | - Xiebin Gu
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | | | - Clary A Clish
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Jeffrey A Porter
- Novartis Institutes for Biomedical Research Inc., Cambridge, MA 02139, USA
| | - Hera Vlamakis
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Center for Microbiome Informatics and Therapeutics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Ramnik J Xavier
- Center for Computational and Integrative Biology, Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Center for Microbiome Informatics and Therapeutics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
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19
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Liu H, Shiver AL, Price MN, Carlson HK, Trotter VV, Chen Y, Escalante V, Ray J, Hern KE, Petzold CJ, Turnbaugh PJ, Huang KC, Arkin AP, Deutschbauer AM. Functional genetics of human gut commensal Bacteroides thetaiotaomicron reveals metabolic requirements for growth across environments. Cell Rep 2021; 34:108789. [PMID: 33657378 PMCID: PMC8121099 DOI: 10.1016/j.celrep.2021.108789] [Citation(s) in RCA: 74] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 11/30/2020] [Accepted: 02/03/2021] [Indexed: 12/12/2022] Open
Abstract
Harnessing the microbiota for beneficial outcomes is limited by our poor understanding of the constituent bacteria, as the functions of most of their genes are unknown. Here, we measure the growth of a barcoded transposon mutant library of the gut commensal Bacteroides thetaiotaomicron on 48 carbon sources, in the presence of 56 stress-inducing compounds, and during mono-colonization of gnotobiotic mice. We identify 516 genes with a specific phenotype under only one or a few conditions, enabling informed predictions of gene function. For example, we identify a glycoside hydrolase important for growth on type I rhamnogalacturonan, a DUF4861 protein for glycosaminoglycan utilization, a 3-keto-glucoside hydrolase for disaccharide utilization, and a tripartite multidrug resistance system specifically for bile salt tolerance. Furthermore, we show that B. thetaiotaomicron uses alternative enzymes for synthesizing nitrogen-containing metabolic precursors based on ammonium availability and that these enzymes are used differentially in vivo in a diet-dependent manner.
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Affiliation(s)
- Hualan Liu
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Anthony L Shiver
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Morgan N Price
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Hans K Carlson
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Valentine V Trotter
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Yan Chen
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Veronica Escalante
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Jayashree Ray
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Kelsey E Hern
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Christopher J Petzold
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Peter J Turnbaugh
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
| | - Kerwyn Casey Huang
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Adam P Arkin
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Adam M Deutschbauer
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
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20
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Iablokov SN, Klimenko NS, Efimova DA, Shashkova T, Novichkov PS, Rodionov DA, Tyakht AV. Metabolic Phenotypes as Potential Biomarkers for Linking Gut Microbiome With Inflammatory Bowel Diseases. Front Mol Biosci 2021; 7:603740. [PMID: 33537340 PMCID: PMC7848230 DOI: 10.3389/fmolb.2020.603740] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 12/09/2020] [Indexed: 12/13/2022] Open
Abstract
The gut microbiome is of utmost importance to human health. While a healthy microbiome can be represented by a variety of structures, its functional capacity appears to be more important. Gene content of the community can be assessed by “shotgun” metagenomics, but this approach is still too expensive. High-throughput amplicon-based surveys are a method of choice for large-scale surveys of links between microbiome, diseases, and diet, but the algorithms for predicting functional composition need to be improved to achieve good precision. Here we show how feature engineering based on microbial phenotypes, an advanced method for functional prediction from 16S rRNA sequencing data, improves identification of alterations of the gut microbiome linked to the disease. We processed a large collection of published gut microbial datasets of inflammatory bowel disease (IBD) patients to derive their community phenotype indices (CPI)—high-precision semiquantitative profiles aggregating metabolic potential of the community members based on genome-wide metabolic reconstructions. The list of selected metabolic functions included metabolism of short-chain fatty acids, vitamins, and carbohydrates. The machine-learning approach based on microbial phenotypes allows us to distinguish the microbiome profiles of healthy controls from patients with Crohn's disease and from ones with ulcerative colitis. The classifiers were comparable in quality to conventional taxonomy-based classifiers but provided new findings giving insights into possible mechanisms of pathogenesis. Feature-wise partial dependence plot (PDP) analysis of contribution to the classification result revealed a diversity of patterns. These observations suggest a constructive basis for defining functional homeostasis of the healthy human gut microbiome. The developed features are promising interpretable candidate biomarkers for assessing microbiome contribution to disease risk for the purposes of personalized medicine and clinical trials.
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Affiliation(s)
- Stanislav N Iablokov
- A.A. Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia.,P.G. Demidov Yaroslavl State University, Yaroslavl, Russia
| | - Natalia S Klimenko
- Atlas Biomed Group-Knomics LLC, London, United Kingdom.,Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | | | - Tatiana Shashkova
- Atlas Biomed Group-Knomics LLC, London, United Kingdom.,Moscow Institute of Physics and Technology, Moscow, Russia
| | - Pavel S Novichkov
- PhenoBiome Inc., San Francisco, CA, United States.,Lawrence Berkeley National Lab, Berkeley, CA, United States
| | - Dmitry A Rodionov
- A.A. Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia.,Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA, United States
| | - Alexander V Tyakht
- Atlas Biomed Group-Knomics LLC, London, United Kingdom.,Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
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21
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Briggs JA, Grondin JM, Brumer H. Communal living: glycan utilization by the human gut microbiota. Environ Microbiol 2020; 23:15-35. [PMID: 33185970 DOI: 10.1111/1462-2920.15317] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 11/06/2020] [Accepted: 11/09/2020] [Indexed: 12/15/2022]
Abstract
Our lower gastrointestinal tract plays host to a vast consortium of microbes, known as the human gut microbiota (HGM). The HGM thrives on a complex and diverse range of glycan structures from both dietary and host sources, the breakdown of which requires the concerted action of cohorts of carbohydrate-active enzymes (CAZymes), carbohydrate-binding proteins, and transporters. The glycan utilization profile of individual taxa, whether 'specialist' or 'generalist', is dictated by the number and functional diversity of these glycan utilization systems. Furthermore, taxa in the HGM may either compete or cooperate in glycan deconstruction, thereby creating a complex ecological web spanning diverse nutrient niches. As a result, our diet plays a central role in shaping the composition of the HGM. This review presents an overview of our current understanding of glycan utilization by the HGM on three levels: (i) molecular mechanisms of individual glycan deconstruction and uptake by key bacteria, (ii) glycan-mediated microbial interactions, and (iii) community-scale effects of dietary changes. Despite significant recent advancements, there remains much to be discovered regarding complex glycan metabolism in the HGM and its potential to affect positive health outcomes.
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Affiliation(s)
- Jonathon A Briggs
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Julie M Grondin
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Harry Brumer
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.,Department of Chemistry, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.,Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.,Department of Botany, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
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22
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Glowacki RWP, Martens EC. If you eat it, or secrete it, they will grow: the expanding list of nutrients utilized by human gut bacteria. J Bacteriol 2020; 203:JB.00481-20. [PMID: 33168637 PMCID: PMC8092160 DOI: 10.1128/jb.00481-20] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
In order to persist, successful bacterial inhabitants of the human gut need to adapt to changing nutrient conditions, which are influenced by host diet and a variety of other factors. For members of the Bacteroidetes and several other phyla, this has resulted in diversification of a variety of enzyme-based systems that equip them to sense and utilize carbohydrate-based nutrients from host, diet, and bacterial origin. In this review, we focus first on human gut Bacteroides and describe recent findings regarding polysaccharide utilization loci (PULs) and the mechanisms of the multi-protein systems they encode, including their regulation and the expanding diversity of substrates that they target. Next, we highlight previously understudied substrates such as monosaccharides, nucleosides, and Maillard reaction products that can also affect the gut microbiota by feeding symbionts that possess specific systems for their metabolism. Since some pathogens preferentially utilize these nutrients, they may represent nutrient niches competed for by commensals and pathogens. Finally, we address recent work to describe nutrient acquisition mechanisms in other important gut species such as those belonging to the Gram-positive anaerobic phyla Actinobacteria and Firmicutes, as well as the Proteobacteria Because gut bacteria contribute to many aspects of health and disease, we showcase advances in the field of synthetic biology, which seeks to engineer novel, diet-controlled nutrient utilization pathways within gut symbionts to create rationally designed live therapeutics.
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Affiliation(s)
- Robert W. P. Glowacki
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Eric C. Martens
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
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23
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Munoz J, James K, Bottacini F, Van Sinderen D. Biochemical analysis of cross-feeding behaviour between two common gut commensals when cultivated on plant-derived arabinogalactan. Microb Biotechnol 2020; 13:1733-1747. [PMID: 32385941 PMCID: PMC7533333 DOI: 10.1111/1751-7915.13577] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 03/30/2020] [Accepted: 03/30/2020] [Indexed: 12/12/2022] Open
Abstract
In this paper, we reveal and characterize cross-feeding behaviour between the common gut commensal Bacteroides cellulosilyticus (Baccell) and certain bifidobacterial strains, including Bifidobacterium breve UCC2003, when grown on a medium containing Larch Wood Arabinogalactan (LW-AG). We furthermore show that cross-feeding is dependent on the release of β-1,3-galacto-di/trisaccharides (β-1,3-GOS), and identified that the bga gene cluster of B. breve UCC2003 allows β-1,3-GOS metabolism. The product of bgaB is presumed to be responsible for the import of β-1,3-GOS, while the bgaA gene product, a glycoside hydrolase family 2 member, was shown to hydrolyse both β-1,3-galactobiose and β-1,3-galactotriose into galactose monomers. This study advances our understanding of strain-specific syntrophic interactions between two glycan degraders in the human gut in the presence of AG-type dietary polysaccharides.
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Affiliation(s)
- Jose Munoz
- Microbial Enzymology GroupDepartment of Applied SciencesNorthumbria UniversityNewcastle Upon TyneNE1 8STUK
| | - Kieran James
- School of Microbiology & APC Microbiome IrelandUniversity College CorkIreland University College CorkCorkIreland
| | - Francesca Bottacini
- School of Microbiology & APC Microbiome IrelandUniversity College CorkIreland University College CorkCorkIreland
| | - Douwe Van Sinderen
- School of Microbiology & APC Microbiome IrelandUniversity College CorkIreland University College CorkCorkIreland
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24
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Abstract
Dietary fiber is known to influence symbiotic gut microbiota community structure and physiology; however, how and if dietary fiber can induce further exogenous nutrient uptake within gut microbes is ill-defined. Recent findings highlight how during periods of high-fiber consumption, a prevalent gut bacteria senses and scavenges the ubiquitous sugar ribose. This molecular adaptation exemplifies how particular gut microbes have developed a sophisticated system to scavenge nutrients in a diet-dependent manner.
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Affiliation(s)
- Vivekanudeep Karri
- Department of Biosciences, School of Natural Sciences, Rice University, Houston, TX, USA
| | - Kendal D. Hirschi
- Children’s Nutrition Research Center, Baylor College of Medicine, Houston, TX, USA,CONTACT Kendal D. Hirschi Children’s Nutrition Research Center, Baylor College of Medicine, Houston, Texas, USA
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25
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Porter NT, Hryckowian AJ, Merrill BD, Fuentes JJ, Gardner JO, Glowacki RWP, Singh S, Crawford RD, Snitkin ES, Sonnenburg JL, Martens EC. Phase-variable capsular polysaccharides and lipoproteins modify bacteriophage susceptibility in Bacteroides thetaiotaomicron. Nat Microbiol 2020; 5:1170-1181. [PMID: 32601452 PMCID: PMC7482406 DOI: 10.1038/s41564-020-0746-5] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 05/27/2020] [Indexed: 12/22/2022]
Abstract
A variety of cell surface structures dictate interactions between bacteria and their environment, including their viruses (bacteriophages). Members of the human gut Bacteroidetes characteristically produce several phase-variable capsular polysaccharides (CPSs), but their contributions to bacteriophage interactions are unknown. To begin to understand how CPSs have an impact on Bacteroides-phage interactions, we isolated 71 Bacteroides thetaiotaomicron-infecting bacteriophages from two locations in the United States. Using B. thetaiotaomicron strains that express defined subsets of CPSs, we show that CPSs dictate host tropism for these phages and that expression of non-permissive CPS variants is selected under phage predation, enabling survival. In the absence of CPSs, B. thetaiotaomicron escapes bacteriophage predation by altering expression of eight distinct phase-variable lipoproteins. When constitutively expressed, one of these lipoproteins promotes resistance to multiple bacteriophages. Our results reveal important roles for Bacteroides CPSs and other cell surface structures that allow these bacteria to persist under bacteriophage predation, and hold important implications for using bacteriophages therapeutically to target gut symbionts.
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Affiliation(s)
- Nathan T Porter
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA
| | - Andrew J Hryckowian
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA.
| | - Bryan D Merrill
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA
| | - Jaime J Fuentes
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA
| | - Jackson O Gardner
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA
| | - Robert W P Glowacki
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA
| | - Shaleni Singh
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA
| | - Ryan D Crawford
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Evan S Snitkin
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA
| | - Justin L Sonnenburg
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA
| | - Eric C Martens
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA.
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26
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Shen J, Ding Y, Yang Z, Zhang X, Zhao M. Effects of changes on gut microbiota in children with acute Kawasaki disease. PeerJ 2020; 8:e9698. [PMID: 33005487 PMCID: PMC7512135 DOI: 10.7717/peerj.9698] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 07/20/2020] [Indexed: 01/15/2023] Open
Abstract
Background Kawasaki disease (KD) is an acute febrile illness of early childhood. The exact etiology of the disease remains unknown. At present, research on KD is mostly limited to susceptibility genes, infections, and immunity. However, research on the correlation between gut microbiota and KD is rare. Methods Children with a diagnosis of acute KD and children undergoing physical examination during the same period were included. At the time of admission, the subjects’ peripheral venous blood and feces were collected. Faecal samples were analyzed for bacterial taxonomic content via high-throughput sequencing. The abundance, diversity, composition, and characteristic differences of the gut microbiota in KD and healthy children were compared by alpha diversity, beta diversity, linear discriminant analysis and LDA effect size analysis. Blood samples were used for routine blood examination, biochemical analysis, and immunoglobulin quantitative detection. Results Compared with the control group, the community richness and structure of gut microbiota in the KD group was significantly reduced (Chao1 richness estimator, mean 215.85 in KD vs. mean 725.76 in control, p < 0.01; Shannon diversity index, mean 3.32 in KD vs. mean 5.69 in control, p < 0.05). LEfSe analysis identified two strains of bacteria significantly associated with KD: Bacteroidetes and Dorea. Bacteroidetes were enriched in healthy children (mean 0.16 in KD vs. mean 0.34 in control, p < 0.05). Dorea was also enriched in healthy children but rarely existed in children with KD (mean 0.002 in KD vs. mean 0.016 in control, p < 0.05). Compared with the control, IgA and IgG in the KD group decreased (IgA, median 0.68 g/L in KD vs. median 1.06 g/L in control, p < 0.001; IgG, median 6.67 g/L in KD vs. median 9.71 g/L in control, p < 0.001), and IgE and IgM levels were not significantly changed. Conclusions Dysbiosis of gut microbiota occurs in children with acute KD and may be related to the etiology or pathogenesis of KD. It is worth noting that for the first time, we found that Dorea, a hydrogen-producing bacterium, was significantly reduced in children with acute KD. Overall, our results provide a theoretical basis for the prevention or diagnosis of KD based on intestinal microecology.
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Affiliation(s)
- Jie Shen
- Department of Pediatrics, The Third Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Yinghe Ding
- Department of Pediatrics, The Third Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Zuocheng Yang
- Department of Pediatrics, The Third Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Xueyan Zhang
- Department of Pediatrics, The Third Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Mingyi Zhao
- Department of Pediatrics, The Third Xiangya Hospital, Central South University, Changsha, Hunan Province, China
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27
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Abstract
Bacteroides genomes encode a large repertoire of proteins dedicated to the utilization of diverse plant polysaccharides and host glycans. In this issue of Cell Host & Microbe, Glowacki et al. (2020) show that B. thetaiotaomicron can also extract the monosaccharide ribose from nucleosides and characterize proteins necessary for its utilization.
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