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Emergent evolutionary forces in spatial models of luminal growth and their application to the human gut microbiota. Proc Natl Acad Sci U S A 2022; 119:e2114931119. [PMID: 35787046 PMCID: PMC9282425 DOI: 10.1073/pnas.2114931119] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The genetic composition of the gut microbiota is constantly reshaped by ecological and evolutionary forces. These strain-level dynamics are challenging to understand because they depend on complex spatial growth processes that take place within a host. Here we introduce a population genetic framework to predict how stochastic evolutionary forces emerge from simple models of microbial growth in spatially extended environments like the intestinal lumen. Our framework shows how fluid flow and longitudinal variation in growth rate combine to shape the frequencies of genetic variants in simulated fecal samples, yielding analytical expressions for the effective generation times, selection coefficients, and rates of genetic drift. We find that over longer timescales, the emergent evolutionary dynamics can often be captured by well-mixed models that lack explicit spatial structure, even when there is substantial spatial variation in species-level composition. By applying these results to the human colon, we find that continuous fluid flow and simple forms of wall growth alone are unlikely to create sufficient bottlenecks to allow large fluctuations in mutant frequencies within a host. We also find that the effective generation times may be significantly shorter than expected from traditional average growth rate estimates. Our results provide a starting point for quantifying genetic turnover in spatially extended settings like the gut microbiota and may be relevant for other microbial ecosystems where unidirectional fluid flow plays an important role.
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Ge Y, Zadeh M, Mohamadzadeh M. Vitamin B12 coordinates ileal epithelial cell and microbiota functions to resist Salmonella infection in mice. J Exp Med 2022; 219:213271. [PMID: 35674742 DOI: 10.1084/jem.20220057] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 04/15/2022] [Accepted: 05/25/2022] [Indexed: 12/15/2022] Open
Abstract
Deprivation of vitamin B12 (VB12) is linked to various diseases, but the underlying mechanisms in disease progression are poorly understood. Using multiomic approaches, we elucidated the responses of ileal epithelial cells (iECs) and gut microbiome to VB12 dietary restriction. Here, VB12 deficiency impaired the transcriptional and metabolic programming of iECs and reduced epithelial mitochondrial respiration and carnitine shuttling during intestinal Salmonella Typhimurium (STm) infection. Fecal microbial and untargeted metabolomic profiling identified marked changes related to VB12 deficiency, including reductions of metabolites potentially activating mitochondrial β-oxidation in iECs and short-chain fatty acids (SCFAs). Depletion of SCFA-producing microbes by streptomycin treatment decreased the VB12-dependent STm protection. Moreover, compromised mitochondrial function of iECs correlated with declined cell capability to utilize oxygen, leading to uncontrolled oxygen-dependent STm expansion in VB12-deficient mice. Our findings uncovered previously unrecognized mechanisms through which VB12 coordinates ileal epithelial mitochondrial homeostasis and gut microbiota to regulate epithelial oxygenation, resulting in the control of aerobic STm infection.
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Affiliation(s)
- Yong Ge
- Division of Gastroenterology & Nutrition, Department of Medicine, University of Texas Health, San Antonio, TX.,Department of Infectious Diseases & Immunology, University of Florida, Gainesville, FL
| | - Mojgan Zadeh
- Division of Gastroenterology & Nutrition, Department of Medicine, University of Texas Health, San Antonio, TX.,Department of Infectious Diseases & Immunology, University of Florida, Gainesville, FL
| | - Mansour Mohamadzadeh
- Division of Gastroenterology & Nutrition, Department of Medicine, University of Texas Health, San Antonio, TX.,Department of Infectious Diseases & Immunology, University of Florida, Gainesville, FL
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Kim MB, Hwangbo S, Jang S, Jo YK. Bioengineered Co-culture of organoids to recapitulate host-microbe interactions. Mater Today Bio 2022; 16:100345. [PMID: 35847376 PMCID: PMC9283667 DOI: 10.1016/j.mtbio.2022.100345] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 06/26/2022] [Accepted: 06/27/2022] [Indexed: 11/05/2022] Open
Abstract
The recent spike in the instances of complex physiological host-microbe interactions has raised the demand for developing in vitro models that recapitulate the microbial microenvironment in the human body. Organoids are steadily emerging as an in vitro culture system that closely mimics the structural, functional, and genetic features of complex human organs, particularly for better understanding host-microbe interactions. Recent advances in organoid culture technology have become new avenues for assessing the pathogenesis of symbiotic interactions, pathogen-induced infectious diseases, and various other diseases. The co-cultures of organoids with microbes have shown great promise in simulating host-microbe interactions with a high level of complexity for further advancement in related fields. In this review, we provide an overview of bioengineering approaches for microbe-co-cultured organoids. Latest developments in the applications of microbe-co-cultured organoids to study human physiology and pathophysiology are also highlighted. Further, an outlook on future research on bioengineered organoid co-cultures for various applications is presented.
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Abstract
Changes in the composition of the gut microbiota are associated with many human diseases. So far, however, we have failed to define homeostasis or dysbiosis by the presence or absence of specific microbial species. The composition and function of the adult gut microbiota is governed by diet and host factors that regulate and direct microbial growth. The host delivers oxygen and nitrate to the lumen of the small intestine, which selects for bacteria that use respiration for energy production. In the colon, by contrast, the host limits the availability of oxygen and nitrate, which results in a bacterial community that specializes in fermentation for growth. Although diet influences microbiota composition, a poor diet weakens host control mechanisms that regulate the microbiota. Hence, quantifying host parameters that control microbial growth could help define homeostasis or dysbiosis and could offer alternative strategies to remediate dysbiosis.
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Affiliation(s)
- Jee-Yon Lee
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA 95616, USA
| | - Renée M Tsolis
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA 95616, USA
| | - Andreas J Bäumler
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA 95616, USA
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55
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Yan Y, Wang J, Qiu S, Duan Y, Si W. The Lumenal Microbiota Varies Biogeographically in the Gastrointestinal Tract of Rhesus Macaques. Microbiol Spectr 2022; 10:e0034322. [PMID: 35499338 PMCID: PMC9241614 DOI: 10.1128/spectrum.00343-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 04/11/2022] [Indexed: 11/20/2022] Open
Abstract
The strategy of adjusting the composition of gastrointestinal microbiota has shown great promise for the treatment of diseases. Currently, the relationship between gut microbes and human diseases is mainly presented by the fecal microbiota from the colon. Due to the limits of sampling, the healthy baseline of biogeographic microbiota in the human gastrointestinal tract remains blurry. Captive nonhuman primates (NHPs) present a "humanized" intestinal microbiome and may make up for the lack of atlas data for better understanding of the gut microbial composition and diseases. Therefore, the intestinal microbiota of 6 GIT regions of healthy rhesus monkeys were analyzed in this study; our results showed that Proteobacteria gradually decreased from the small intestine to the large intestine but Bacteroidetes gradually increased from the small intestine to the large intestine. Streptococcus and Lactobacillus can be used as markers to distinguish the small intestine from the large intestine. Sarcina is the most enriched in the middle site of the connection between the large intestine and the small intestine. Cyanobacteria are enriched in the small intestine, especially the duodenum and jejunum, and are absent in the large intestine. The lumenal microbiota of the small intestine is more susceptible to individual differences than is that of the large intestine. Metabolism and oxygen affect the distribution of the microbes, and the diversity of microbiota is the highest in the colon. Our results provide accurate comprehensive GIT microbiota data on nonhuman primates and will be beneficial for the better understanding of the composition of microbiota in the human gastrointestinal tract. IMPORTANCE For the study of upper gastrointestinal microbiota in humans, endoscopic sampling is the main source of information, which limits the understanding of healthy upper gastrointestinal microbiota. Rhesus monkeys show very close similarity to humans in physiology, genetics, and behavior and act as the most suitable animal models for human diseases. The present research made up for the lack of atlas data due to the ethical limitations of sampling in humans and provided baseline data on microbiota in 6 GIT regions of healthy NHPs. These important references will be beneficial for the better understanding of the regional organization and functions of gut microbial communities along the GIT and their relevance to conditions of health and disease.
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Affiliation(s)
- Yaping Yan
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, Yunnan, China
| | - Junfeng Wang
- Digital Medical Research Center, Department of Hepatobiliary Surgery, the First People’s Hospital of Yunnan Province, Kunhua Hospital Affiliated to Kunming University of Science and Technology, Kunming, China
| | - Shuai Qiu
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, Yunnan, China
| | - Yanchao Duan
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, Yunnan, China
| | - Wei Si
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, Yunnan, China
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Evolutionary Adaptations of Parasitic Flatworms to Different Oxygen Tensions. Antioxidants (Basel) 2022; 11:antiox11061102. [PMID: 35739999 PMCID: PMC9220675 DOI: 10.3390/antiox11061102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 05/25/2022] [Accepted: 05/29/2022] [Indexed: 11/17/2022] Open
Abstract
During the evolution of the Earth, the increase in the atmospheric concentration of oxygen gave rise to the development of organisms with aerobic metabolism, which utilized this molecule as the ultimate electron acceptor, whereas other organisms maintained an anaerobic metabolism. Platyhelminthes exhibit both aerobic and anaerobic metabolism depending on the availability of oxygen in their environment and/or due to differential oxygen tensions during certain stages of their life cycle. As these organisms do not have a circulatory system, gas exchange occurs by the passive diffusion through their body wall. Consequently, the flatworms developed several adaptations related to the oxygen gradient that is established between the aerobic tegument and the cellular parenchyma that is mostly anaerobic. Because of the aerobic metabolism, hydrogen peroxide (H2O2) is produced in abundance. Catalase usually scavenges H2O2 in mammals; however, this enzyme is absent in parasitic platyhelminths. Thus, the architecture of the antioxidant systems is different, depending primarily on the superoxide dismutase, glutathione peroxidase, and peroxiredoxin enzymes represented mainly in the tegument. Here, we discuss the adaptations that parasitic flatworms have developed to be able to transit from the different metabolic conditions to those they are exposed to during their life cycle.
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Panigrahi MK, Kaliaperumal V, Akella A, Venugopal G, Ramadass B. Mapping microbiome-redox spectrum and evaluating Microbial-Redox Index in chronic gastritis. Sci Rep 2022; 12:8450. [PMID: 35589904 PMCID: PMC9120160 DOI: 10.1038/s41598-022-12431-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 05/11/2022] [Indexed: 12/27/2022] Open
Abstract
Peptic ulcer disease (PUD) and chronic gastritis are prevalent in developing countries. The role of oxidative stress in the pathogenesis of gastrointestinal mucosal disorders is well recognized. In PUD, the gastric mucosa and its associated microbiome are subject to diet and stress-induced oxidative perturbations. Tissue redox potential (ORP) measurement can quantify oxidative stress, reflecting the balance between prooxidants and antioxidants. This study hypothesizes that the oxidative stress quantified by tissue ORP will be associated with characteristic changes in the mucosa-associated microbiome in PUD and gastritis. In addition, we propose using relative microbial abundance as a quantitative marker of mucosal health. Endoscopy was performed to obtain gastric mucosal biopsies from ten PUD and ten non-ulcer dyspepsia (NUD) patients. The tissue ORP was measured directly with a microelectrode using a biopsy specimen. A second specimen from an adjacent site was subjected to 16s rRNA gene sequencing. From the OTUs, the relative abundance of the microbial taxon in each of the samples was derived. We analyzed the genome of the predominant species for genes encoding the utilization of oxygen as an electron acceptor in respiration and for the presence of antioxidant defense mechanisms. The organisms were then grouped based on their established and inferred redox traits. Shannon diversity index and Species richness were calculated on rarefied data. The relative abundance of organisms that prefer high ORP over those that favor low ORP is conceived as the “Microbial Redox Index (MRI),” an indicator of mucosal health. In the gastric mucosa, aerobic species predominate and are more diverse than the anaerobes. The predominant aerobes are Helicobacter pylori and Sphingobacterium mizutaii. The abundance of these two species had an inverse correlation with the abundance of low ORP preferring anaerobes. Their relative abundance ratio (Microbial Redox Index) correlated with the tissue oxidation–reduction potential (ORP), a direct measure of oxidative stress. Correlation analysis also revealed that the abundance of all anaerobes inversely correlated with the dominant aerobic taxa. In addition, Shannon and Species richness diversity indices, the probable indicators of mucosal health, were negatively correlated with Microbial Redox Index. Using PUD as a prototype mucosal disease, this article describes a generalized approach to infer and quantify mucosal oxidative stress by analyzing the relative abundance of microorganisms that preferentially grow at the extremes of the tissue redox potential. This ratiometric Microbial Redox Index can also be assessed using simple qPCR without the need for sequencing. The approach described herein may be helpful as a widely applicable quantitative measure of mucosal health with prognostic and therapeutic implications.
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Affiliation(s)
- Manas Kumar Panigrahi
- Department of Gastroenterology, All India Institute of Medical Sciences, Bhubaneswar, India
| | - Venkatesh Kaliaperumal
- MYAS-NIN Department of Sports Science, ICMR-National Institute of Nutrition, Hyderabad, India
| | - Abhishek Akella
- Center of Excellence for Clinical Microbiome Research, All India Institute of Medical Sciences, Bhubaneswar, 751019, India
| | - Giriprasad Venugopal
- Center of Excellence for Clinical Microbiome Research, All India Institute of Medical Sciences, Bhubaneswar, 751019, India
| | - Balamurugan Ramadass
- Center of Excellence for Clinical Microbiome Research, All India Institute of Medical Sciences, Bhubaneswar, 751019, India. .,Department of Biochemistry, All India Institute of Medical Sciences, Bhubaneswar, India.
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58
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Significance of Mucosa-Associated Microbiota and Its Impacts on Intestinal Health of Pigs Challenged with F18 +E. coli. Pathogens 2022; 11:pathogens11050589. [PMID: 35631110 PMCID: PMC9145386 DOI: 10.3390/pathogens11050589] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 05/05/2022] [Accepted: 05/14/2022] [Indexed: 01/27/2023] Open
Abstract
The objective of this study was to evaluate the significance of jejunal mucosa-associated microbiota and its impacts on the intestinal health of pigs challenged with F18+ Escherichia coli. Forty-four newly-weaned pigs were allotted to two treatments in a randomized complete block design with sex as blocks. Pigs were fed common diets for 28 d. At d 7 post-weaning, pigs were orally inoculated with saline solution or F18+ E. coli. At d 21 post-challenge, feces and blood were collected and pigs were euthanized to collect jejunal tissue to evaluate microbiota and intestinal health parameters. The relative abundance of Firmicutes and Bacteroidetes was lower (p < 0.05) in jejunal mucosa than in feces, whereas Proteobacteria was greater (p < 0.05) in jejunal mucosa. F18+ E. coli increased (p < 0.05) protein carbonyl, Helicobacteraceae, Pseudomonadaceae, Xanthomonadaceae, and Peptostreptococcaceae and reduced (p < 0.05) villus height, Enterobacteriaceae, Campylobacteraceae, Brachyspiraceae, and Caulobacteraceae in jejunal mucosa, whereas it reduced (p < 0.05) Spirochaetaceae and Oscillospiraceae in feces. Collectively, jejunal mucosa-associated microbiota differed from those in feces. Compared with fecal microbiota, the change of mucosa-associated microbiota by F18+ E. coli was more prominent, and it was mainly correlated with increased protein carbonyl and reduced villus height in jejunal mucosa impairing the intestinal health of nursery pigs.
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59
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Zhao R, Li Z, Sun Y, Ge W, Wang M, Liu H, Xun L, Xia Y. Engineered Escherichia coli Nissle 1917 with urate oxidase and an oxygen-recycling system for hyperuricemia treatment. Gut Microbes 2022; 14:2070391. [PMID: 35491895 PMCID: PMC9067508 DOI: 10.1080/19490976.2022.2070391] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Hyperuricemia is the second most prevalent metabolic disease to human health after diabetes. Only a few clinical drugs are available, and most of them have serious side effects. The human body does not have urate oxidase, and uric acid is secreted via the kidney or the intestine. Reduction through kidney secretion is often the cause of hyperuricemia. We hypothesized that the intestine secretion could be enhanced when a recombinant urate-degrading bacterium was introduced into the gut. We engineered an Escherichia coli Nissle 1917 strain with a plasmid containing a gene cassette that encoded two proteins PucL and PucM for urate metabolism from Bacillus subtilis, the urate importer YgfU and catalase KatG from E. coli, and the bacterial hemoglobin Vhb from Vitreoscilla sp. The recombinant E. coli strain effectively degraded uric acid under hypoxic conditions. A new method to induce hyperuricemia in mice was developed by intravenously injecting uric acid. The engineered Escherichia coli strain significantly lowered the serum uric acid when introduced into the gut or directly injected into the blood vessel. The results support the use of urate-degrading bacteria in the gut to treat hyperuricemia. Direct injecting bacteria into blood vessels to treat metabolic diseases is proof of concept, and it has been tried to treat solid tumors.
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Affiliation(s)
- Rui Zhao
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, Shandong Province, China
| | - Zimai Li
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, Shandong Province, China
| | - Yuqing Sun
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, Shandong Province, China
| | - Wei Ge
- Clinical Laboratory, Qingdao Fuwai Cardiovascular Hospital, Qingdao, Shandong Province, China
| | - Mingyu Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, Shandong Province, China
| | - Huaiwei Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, Shandong Province, China
| | - Luying Xun
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, Shandong Province, China,School of Molecular Biosciences, Washington State University, Pullman, WA, USA
| | - Yongzhen Xia
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, Shandong Province, China,CONTACT Yongzhen Xia State Key Laboratory of Microbial Technology, Shandong University, Qingdao, Shandong Province266237, People’s Republic of China
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60
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Van Alst AJ, Demey LM, DiRita VJ. Vibrio cholerae requires oxidative respiration through the bd-I and cbb3 oxidases for intestinal proliferation. PLoS Pathog 2022; 18:e1010102. [PMID: 35500027 PMCID: PMC9109917 DOI: 10.1371/journal.ppat.1010102] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 05/16/2022] [Accepted: 04/05/2022] [Indexed: 01/05/2023] Open
Abstract
Vibrio cholerae respires both aerobically and anaerobically and, while oxygen may be available to it during infection, other terminal electron acceptors are proposed for population expansion during infection. Unlike gastrointestinal pathogens that stimulate significant inflammation leading to elevated levels of oxygen or alternative terminal electron acceptors, V. cholerae infections are not understood to induce a notable inflammatory response. To ascertain the respiration requirements of V. cholerae during infection, we used Multiplex Genome Editing by Natural Transformation (MuGENT) to create V. cholerae strains lacking aerobic or anaerobic respiration. V. cholerae strains lacking aerobic respiration were attenuated in infant mice 105-fold relative to wild type, while strains lacking anaerobic respiration had no colonization defect, contrary to earlier work suggesting a role for anaerobic respiration during infection. Using several approaches, including one we developed for this work termed Comparative Multiplex PCR Amplicon Sequencing (CoMPAS), we determined that the bd-I and cbb3 oxidases are essential for small intestinal colonization of V. cholerae in the infant mouse. The bd-I oxidase was also determined as the primary oxidase during growth outside the host, making V. cholerae the only example of a Gram-negative bacterial pathogen in which a bd-type oxidase is the primary oxidase for energy acquisition inside and outside of a host. The bacterium that causes cholera, Vibrio cholerae, can grow with or without oxygen. When growing without oxygen it may use other molecules that serve the same purpose as oxygen, acting as a terminal electron acceptor in an energy-generating process known as respiration. Given the largely anaerobic nature of the gastrointestinal tract, and the lack of significant inflammation during cholera infection, a process that can stimulate elevated levels of oxygen and other terminal electron acceptors, we sought to understand the respiratory mechanisms of V. cholerae during infection. We used a powerful genome-editing method to construct mutant strains of V. cholerae lacking some or all of the complement of proteins required for aerobic or anaerobic respiration. By analyzing these mutants in the laboratory and in intestinal colonization of infant mice, we determined that the ability to respire without oxygen is completely dispensable for V. cholerae to thrive during infection. We determined that two of the four oxygen-dependent respiration mechanisms are essential for V. cholerae to grow during infection, with the other two dispensable for wild type levels of colonization.
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Affiliation(s)
- Andrew J. Van Alst
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, United States of America
| | - Lucas M. Demey
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, United States of America
| | - Victor J. DiRita
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, United States of America
- * E-mail:
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Han LX, Yao WL, Pan J, Wang BS, He WH, Fan XP, Wang WH, Zhang WD. Moniezia benedeni Infection Restrain IgA+, IgG+, and IgM+ Cells Residence in Sheep (Ovis aries) Small Intestine. Front Vet Sci 2022; 9:878467. [PMID: 35573414 PMCID: PMC9096708 DOI: 10.3389/fvets.2022.878467] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 04/07/2022] [Indexed: 01/12/2023] Open
Abstract
Secreted immunoglobulin A (SIgA), IgG, and IgM play a crucial role in forming the intestinal mucosal immune barrier, and parasites could disturb the host's immune response by releasing various immunomodulatory molecules. Moniezia benedeni is an important pathogen parasitizing in the sheep small intestine. It is aimed to explore the residence characteristics of IgA+, IgG+, and IgM+ cells in the sheep small intestine, and the influence of Moniezia benedeni infection on them. Control group (n = 6) and infected group (n = 6) were selected, respectively, and the three subtype cells residing in the small intestine were systematically observed and analyzed. The results showed that in the Control group, the three types of positive cells were all distributed diffusely, and the total densities in jejunum, duodenum and ileum was gradually declined in turn. Notably, the change trend of IgA+ and IgG+ cells densities were both congruent with the total densities, and the differences among them were significant, respectively (P < 0.05); the IgM+ cells density was the highest in duodenum, followed by jejunum and ileum, there was no significant difference between duodenum and jejunum (P > 0.05), but both significantly higher than in ileum (P < 0.05). In the Infected group, their total densities in duodenum, jejunum and ileum were gradually declined in turn. Notably, the IgA+ and IgM+ cells densities change trend was the same as the total densities, and the differences among them were significant, respectively (P < 0.05). The IgG+ cells density in duodenum was the highest, followed by ileum and jejunum and there was significantly difference among them (P < 0.05). The comparison results between Control and Infected groups showed that from the duodenum, jejunum to ileum, IgA+, IgG+, and IgM+ cells were all reduced significantly, respectively. The results suggest that the three types of positive cells were resided heterogeneously in the small intestinal mucosa, that is, significant region-specificity; Moniezia benedeni infection could not change their diffuse distribution characteristics, but strikingly, reduce their resident densities, and the forming mucosal immune barrier were significantly inhibited. It provided powerful evidence for studying on the molecular mechanism of Moniezia benedeni evasion from immune surveillance by strongly inhibiting the host's mucosal immune barrier.
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Flamholz AI, Newman DK. Microbial communities: The metabolic rate is the trait. Curr Biol 2022; 32:R215-R218. [DOI: 10.1016/j.cub.2022.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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63
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Khatib ME, Van Slyke AL, Velalopoulou A, Kim MM, Shoniyozov K, Allu SR, Diffenderfer EE, Busch TM, Wiersma RD, Koch CJ, Vinogradov SA. Ultrafast Tracking of Oxygen Dynamics during Proton FLASH. Int J Radiat Oncol Biol Phys 2022; 113:624-634. [DOI: 10.1016/j.ijrobp.2022.03.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 02/01/2022] [Accepted: 03/12/2022] [Indexed: 10/18/2022]
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Park NY, Koh A. From the Dish to the Real World: Modeling Interactions between the Gut and Microorganisms in Gut Organoids by Tailoring the Gut Milieu. Int J Stem Cells 2022; 15:70-84. [PMID: 35220293 PMCID: PMC8889331 DOI: 10.15283/ijsc21243] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/25/2022] [Accepted: 01/26/2022] [Indexed: 11/11/2022] Open
Abstract
The advent of human intestinal organoid systems has revolutionized the way we understand the interactions between the human gut and microorganisms given the host tropism of human microorganisms. The gut microorganisms have regionality (i.e., small versus large intestine) and the expression of various virulence factors in pathogens is influenced by the gut milieu. However, the culture conditions, optimized for human intestinal organoids, often do not fully support the proliferation and functionality of gut microorganisms. In addition, the regional identity of human intestinal organoids has not been considered to study specific microorganisms with regional preference. In this review we provide an overview of current efforts to understand the role of microorganisms in human intestinal organoids. Specifically, we will emphasize the importance of matching the regional preference of microorganisms in the gut and tailoring the appropriate luminal environmental conditions (i.e., oxygen, pH, and biochemical levels) for modeling real interactions between the gut and the microorganisms with human intestinal organoids.
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Affiliation(s)
- Na-Young Park
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Korea
| | - Ara Koh
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Korea
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65
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Duarte ME, Kim SW. Intestinal microbiota and its interaction to intestinal health in nursery pigs. ANIMAL NUTRITION (ZHONGGUO XU MU SHOU YI XUE HUI) 2022; 8:169-184. [PMID: 34977387 PMCID: PMC8683651 DOI: 10.1016/j.aninu.2021.05.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 04/20/2021] [Accepted: 05/07/2021] [Indexed: 02/07/2023]
Abstract
The intestinal microbiota has gained increased attention from researchers within the swine industry due to its role in promoting intestinal maturation, immune system modulation, and consequently the enhancement of the health and growth performance of the host. This review aimed to provide updated scientific information on the interaction among intestinal microbiota, dietary components, and intestinal health of pigs. The small intestine is a key site to evaluate the interaction of the microbiota, diet, and host because it is the main site for digestion and absorption of nutrients and plays an important role within the immune system. The diet and its associated components such as feed additives are the main factors affecting the microbial composition and is central in stimulating a beneficial population of microbiota. The microbiota–host interaction modulates the immune system, and, concurrently, the immune system helps to modulate the microbiota composition. The direct interaction between the microbiota and the host is an indication that the mucosa-associated microbiota can be more effective in evaluating its effect on health parameters. It was demonstrated that the mucosa-associated microbiota should be evaluated when analyzing the interaction among diets, microbiota, and health. In addition, supplementation of feed additives aimed to promote the intestinal health of pigs should consider their roles in the modulation of mucosa-associated microbiota as biomarkers to predict the response of growth performance to dietary interventions.
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Affiliation(s)
- Marcos Elias Duarte
- Department of Animal Science, North Carolina State University, Raleigh, NC, 27695, United States
| | - Sung Woo Kim
- Department of Animal Science, North Carolina State University, Raleigh, NC, 27695, United States
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66
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Shelton CD, Yoo W, Shealy NG, Torres TP, Zieba JK, Calcutt MW, Foegeding NJ, Kim D, Kim J, Ryu S, Byndloss MX. Salmonella enterica serovar Typhimurium uses anaerobic respiration to overcome propionate-mediated colonization resistance. Cell Rep 2022; 38:110180. [PMID: 34986344 PMCID: PMC8800556 DOI: 10.1016/j.celrep.2021.110180] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 10/23/2021] [Accepted: 12/06/2021] [Indexed: 12/18/2022] Open
Abstract
The gut microbiota benefits the host by limiting enteric pathogen expansion (colonization resistance), partially via the production of inhibitory metabolites. Propionate, a short-chain fatty acid produced by microbiota members, is proposed to mediate colonization resistance against Salmonella enterica serovar Typhimurium (S. Tm). Here, we show that S. Tm overcomes the inhibitory effects of propionate by using it as a carbon source for anaerobic respiration. We determine that propionate metabolism provides an inflammation-dependent colonization advantage to S. Tm during infection. Such benefit is abolished in the intestinal lumen of Salmonella-infected germ-free mice. Interestingly, S. Tm propionate-mediated intestinal expansion is restored when germ-free mice are monocolonized with Bacteroides thetaiotaomicron (B. theta), a prominent propionate producer in the gut, but not when mice are monocolonized with a propionate-production-deficient B. theta strain. Taken together, our results reveal a strategy used by S. Tm to mitigate colonization resistance by metabolizing microbiota-derived propionate Propionate, a short-chain fatty acid produced by the gut microbiota, is proposed to mediate colonization resistance against Salmonella enterica serovar Typhimurium (S. Tm). Here, Shelton et al. show that nitrate-dependent propionate metabolism fuels pathogen expansion in the inflamed gut, allowing S. Tm to overcome propionate’s inhibitory effects.
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Affiliation(s)
- Catherine D Shelton
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Woongjae Yoo
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Nicolas G Shealy
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Teresa P Torres
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Jacob K Zieba
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - M Wade Calcutt
- Mass Spectrometry Research Center and Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Nora J Foegeding
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Dajeong Kim
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Jinshil Kim
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea; Center for Food Bioconvergence, Seoul National University, Seoul 08826, Republic of Korea
| | - Sangryeol Ryu
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea; Center for Food Bioconvergence, Seoul National University, Seoul 08826, Republic of Korea
| | - Mariana X Byndloss
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Institute of Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Digestive Disease Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Microbiome Innovation Center, Vanderbilt University, Nashville, TN 37235, USA.
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67
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Exploring the universal healthy human gut microbiota around the World. Comput Struct Biotechnol J 2022; 20:421-433. [PMID: 35035791 PMCID: PMC8749183 DOI: 10.1016/j.csbj.2021.12.035] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 12/28/2021] [Accepted: 12/28/2021] [Indexed: 02/08/2023] Open
Abstract
The human gut holds a special place in the study of different microbial environments due to growing evidence that the gut microbiota is related to host health. However, despite extensive research, there is still a lack of knowledge about the core taxa forming the gut microbiota and, moreover, available information is biased towards western microbiomes in both genome databases and most core taxa studies. To tackle these limitations, we tested a database enrichment strategy and analyzed public datasets of whole-genome shotgun data, generated from 545 fecal samples, comprising three gradients of westernization. The NT database was selected as a baseline of biological diversity, subsequently being combined with various studies of interest related to the human microbiota. This enrichment strategy made it possible to improve classification capacity, compared to the original unenriched database, regarding the various lifestyles and populations studied. The effects of incomplete-taxonomy metagenome-assembled genomes on genome database enrichment were also examined, revealing that, while they are helpful, they should be used with caution depending on the taxonomic level of interest. Moreover, in terms of high prevalence, the core analysis revealed a conserved set of bacterial taxa in the healthy human gut microbiota worldwide, despite apparent lifestyle differences. Such taxa show a set of traits, metabolic roles, and ancestral status, making them suitable candidates for a hypothetical phylogenetic core of mutualistic microorganisms co-evolving with the human species.
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68
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Bukharin OV, Andryushchenko SV, Perunova NB, Ivanova EV. Environmental Determination of Indigenous Bifidobacteria of the Human Intestine. HERALD OF THE RUSSIAN ACADEMY OF SCIENCES 2022; 92:629-635. [PMID: 36340323 PMCID: PMC9628474 DOI: 10.1134/s1019331622050033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 04/25/2022] [Accepted: 05/12/2022] [Indexed: 11/09/2022]
Abstract
The environmental determination of indigenous (constantly present) bifidobacteria of the human large intestine is considered in this review. Environmental determination (from the Latin determinere, "I determine") is understood as a set of natural phenomena of a habitat (biotope) that determine the role of indigenous microorganisms in the microbiocenosis. Using the symbiotic approach, an attempt is made to identify the environmental conditions for the habitat of bifidobacteria and their physiological effects in the microsymbiocenosis. The features of indigenous bifidobacteria in terms of their nature have been established: evolutionary-genetic (phylogenetic remoteness, genome conservation, metabolic specialization), biochemical (lysozyme resistance, constitutive acetate production), and physiological (microbial "friend-foe" identification, immunoregulation), which are important in adaptation (persistence) and the provision of mutualistic effects and stability of the bifidoflora in the population.
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Affiliation(s)
- O. V. Bukharin
- Institute for Cellular and Intracellular Symbiosis (ICIS), Ural Branch, Russian Academy of Sciences, Orenburg, Russia
| | - S. V. Andryushchenko
- Institute for Cellular and Intracellular Symbiosis (ICIS), Ural Branch, Russian Academy of Sciences, Orenburg, Russia
| | - N. B. Perunova
- Institute for Cellular and Intracellular Symbiosis (ICIS), Ural Branch, Russian Academy of Sciences, Orenburg, Russia
| | - E. V. Ivanova
- Institute for Cellular and Intracellular Symbiosis (ICIS), Ural Branch, Russian Academy of Sciences, Orenburg, Russia
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69
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Mucosal immunology of the ocular surface. Mucosal Immunol 2022; 15:1143-1157. [PMID: 36002743 PMCID: PMC9400566 DOI: 10.1038/s41385-022-00551-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 05/26/2022] [Accepted: 06/10/2022] [Indexed: 02/04/2023]
Abstract
The eye is a sensory organ exposed to the environment and protected by a mucosal tissue barrier. While it shares a number of features with other mucosal tissues, the ocular mucosal system, composed of the conjunctiva, Meibomian glands, and lacrimal glands, is specialized to address the unique needs of (a) lubrication and (b) host defense of the ocular surface. Not surprisingly, most challenges, physical and immunological, to the homeostasis of the eye fall into those two categories. Dry eye, a dysfunction of the lacrimal glands and/or Meibomian glands, which can both cause, or arise from, sensory defects, including those caused by corneal herpes virus infection, serve as examples of these perturbations and will be discussed ahead. To preserve vision, dense neuronal and immune networks sense various stimuli and orchestrate responses, which must be tightly controlled to provide protection, while simultaneously minimizing collateral damage. All this happens against the backdrop of, and can be modified by, the microorganisms that colonize the ocular mucosa long term, or that are simply transient passengers introduced from the environment. This review will attempt to synthesize the existing knowledge and develop trends in the study of the unique mucosal and immune elements of the ocular surface.
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Prenatal versus Postnatal Initial Colonization of Healthy Neonates' Colon Ecosystem by the Enterobacterium Escherichia coli. Microbiol Spectr 2021; 9:e0037921. [PMID: 34817225 PMCID: PMC8612161 DOI: 10.1128/spectrum.00379-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The human colon is a microbial ecosystem whose initial bacterial colonization in neonates is an important step in establishing a beneficial microbiota for the body's health. This study investigated the occurrence of viable culturable Escherichia coli in first-day meconium versus subsequent days' stool to explore the prenatal versus postnatal initial colonization of the colon by E. coli in healthy neonates. E. coli occurrence was investigated on eosin-methylene blue (EMB) agar, followed by morphological and biochemical characterizations and phylogenetic analysis of 16S rRNA-encoding gene sequences. Viable culturable E. coli was not detected in meconium of healthy male or female neonates delivered either vaginally or by cesarean section. Neonates delivered surgically also showed no E. coli colonization on the second and third days, confirming postnatal colonization of the colon by this enterobacterium. E. coli's initial colonization in the colon of neonates delivered vaginally occurred on the second day, which can be attributed to inoculation from the vaginal canal during delivery and, in comparison to the colonization in neonates delivered surgically, leads to the inference that the bacterium is not originally found in meconium. This study suggests no viability of the meconium microbiome in healthy neonates, possibly due to antimicrobial action in the prenatal colon's meconium protecting babies' gut from infection during delivery. IMPORTANCE The results of this study suggest that the initial postnatal colonization of neonates' colon by beneficial bacteria is a naturally controlled process in which the prenatal colon's meconium might play a role in protecting against infection of the babies' gut during delivery.
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Hernalsteens S, Huang S, Cong HH, Chen XD. The final fate of food: On the establishment of in vitro colon models. Food Res Int 2021; 150:110743. [PMID: 34865762 DOI: 10.1016/j.foodres.2021.110743] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 09/24/2021] [Accepted: 10/06/2021] [Indexed: 02/07/2023]
Abstract
The search for life/health quality has driven the search for a better understanding of food components on the overall individual health, which turns to be intrinsically related to the digestive system. In vitro digestion models are considered an alternative for the in vivo studies for a variety of practical reasons, but further research is still needed concerning the colon model establishment. An effective in vitro colon model should consider all unit operations and transport phenomena, together with chemical and biochemical reactions, material handling and reactor design. Due to the different techniques and dependence on the donor microbiota, it is difficult to obtain a standard protocol with results reproductible in time and space. Furthermore, the colon model should be fed with a representative substrate, thus what happens in upper digestion tract and absorption prior to colon is also of crucial importance. Essentially, there are two ways to think about how to achieve a good and useful in vitro colon model: a complex biomimetic system that provides results comparable with the in vivo studies or a simple system, that despite the fact it could not give physiologically relevant data, it is sufficient to understand the fate of some specific components.
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Affiliation(s)
- Saartje Hernalsteens
- College of Chemistry, Chemical Engineering and Materials Science - Soochow University, China.
| | | | - Hai Hua Cong
- College of Food Science and Engineering - Dalian Ocean University, China
| | - Xiao Dong Chen
- College of Chemistry, Chemical Engineering and Materials Science - Soochow University, China.
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72
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When anaerobes encounter oxygen: mechanisms of oxygen toxicity, tolerance and defence. Nat Rev Microbiol 2021; 19:774-785. [PMID: 34183820 PMCID: PMC9191689 DOI: 10.1038/s41579-021-00583-y] [Citation(s) in RCA: 80] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/19/2021] [Indexed: 02/06/2023]
Abstract
The defining trait of obligate anaerobes is that oxygen blocks their growth, yet the underlying mechanisms are unclear. A popular hypothesis was that these microorganisms failed to evolve defences to protect themselves from reactive oxygen species (ROS) such as superoxide and hydrogen peroxide, and that this failure is what prevents their expansion to oxic habitats. However, studies reveal that anaerobes actually wield most of the same defences that aerobes possess, and many of them have the capacity to tolerate substantial levels of oxygen. Therefore, to understand the structures and real-world dynamics of microbial communities, investigators have examined how anaerobes such as Bacteroides, Desulfovibrio, Pyrococcus and Clostridium spp. struggle and cope with oxygen. The hypoxic environments in which these organisms dwell - including the mammalian gut, sulfur vents and deep sediments - experience episodic oxygenation. In this Review, we explore the molecular mechanisms by which oxygen impairs anaerobes and the degree to which bacteria protect their metabolic pathways from it. The emergent view of anaerobiosis is that optimal strategies of anaerobic metabolism depend upon radical chemistry and low-potential metal centres. Such catalytic sites are intrinsically vulnerable to direct poisoning by molecular oxygen and ROS. Observations suggest that anaerobes have evolved tactics that either minimize the extent to which oxygen disrupts their metabolism or restore function shortly after the stress has dissipated.
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73
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Jung EH, Brauner CJ, Wood CM. Post-prandial respiratory gas and acid-base profiles in the gastrointestinal tract and its venous drainage in freshwater rainbow trout (Oncorhynchus mykiss) and seawater English sole (Parophrys vetulus). Comp Biochem Physiol A Mol Integr Physiol 2021; 265:111123. [PMID: 34856374 DOI: 10.1016/j.cbpa.2021.111123] [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: 07/30/2021] [Revised: 10/15/2021] [Accepted: 11/26/2021] [Indexed: 10/19/2022]
Abstract
The basic respiratory gas and acid-base conditions inside the lumen of the gastrointestinal tract (GIT) and blood draining the tract are largely unestablished in teleost fishes after feeding, though there have been some recent novel discoveries on freshwater rainbow trout (Oncorhynchus mykiss) and seawater English sole (Parophrys vetulus). The present study examined in greater detail the gas (PO2, PCO2, PNH3) and acid-base profiles (pH, [HCO3-], total [ammonia]) in the lumen of the stomach, the anterior, mid, and posterior intestine, as well as the venous drainage (subintestinal and/or hepatic portal vein) of the GIT in these two species 20 h post-feeding. Both species had high PCO2, PNH3, and total [ammonia], and low PO2 (virtual anoxia) in the lumens throughout all sections of the GIT, and high [HCO3-] in the intestine. Total [ammonia], PNH3, and [HCO3-] increased from anterior to posterior intestine in both species. P. vetulus had higher intestinal total [ammonia] and lower [HCO3-] than O. mykiss post feeding, but total [ammonia] was much higher in the stomach of O. mykiss. Despite the extreme conditions in the lumen, both arterial and venous blood showed relatively lower PCO2, total [ammonia] and higher PO2, implying limited equilibration between the two compartments. The higher [HCO3-] and lower total [ammonia] in the intestinal lumen of the freshwater O. mykiss than the seawater P. vetulus suggest the need for future comparative studies using conspecifics fed identical diets but acclimated to the two different salinities in order to understand the potential role of environmental salinity and associated osmoregulatory processes underlying these differences.
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Affiliation(s)
- Ellen H Jung
- Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Bamfield Marine Sciences Centre, Bamfield, BC V0R 1B0, Canada.
| | - Colin J Brauner
- Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
| | - Chris M Wood
- Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Bamfield Marine Sciences Centre, Bamfield, BC V0R 1B0, Canada.
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74
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Béchon N, Ghigo JM. Gut biofilms: Bacteroides as model symbionts to study biofilm formation by intestinal anaerobes. FEMS Microbiol Rev 2021; 46:6440158. [PMID: 34849798 DOI: 10.1093/femsre/fuab054] [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: 08/04/2021] [Accepted: 11/09/2021] [Indexed: 02/06/2023] Open
Abstract
Bacterial biofilms are communities of adhering bacteria that express distinct properties compared to their free-living counterparts, including increased antibiotic tolerance and original metabolic capabilities. Despite the potential impact of the biofilm lifestyle on the stability and function of the dense community of micro-organisms constituting the mammalian gut microbiota, the overwhelming majority of studies performed on biofilm formation by gut bacteria focused either on minor and often aerobic members of the community or on pathogenic bacteria. In this review, we discuss the reported evidence for biofilm-like structures formed by gut bacteria, the importance of considering the anaerobic nature of gut biofilms and we present the most recent advances on biofilm formation by Bacteroides, one of the most abundant genera of the human gut microbiota. Bacteroides species can be found attached to food particles and colonizing the mucus layer and we propose that Bacteroides symbionts are relevant models to probe the physiology of gut microbiota biofilms.
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Affiliation(s)
- Nathalie Béchon
- Institut Pasteur, Université de Paris, UMR CNRS2001, Genetics of Biofilms Laboratory 75015 Paris, France
| | - Jean-Marc Ghigo
- Institut Pasteur, Université de Paris, UMR CNRS2001, Genetics of Biofilms Laboratory 75015 Paris, France
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Mukherjee P, Chattopadhyay A, Grijalva V, Dorreh N, Lagishetty V, Jacobs JP, Clifford BL, Vallim T, Mack JJ, Navab M, Reddy ST, Fogelman AM. Oxidized phospholipids cause changes in jejunum mucus that induce dysbiosis and systemic inflammation. J Lipid Res 2021; 63:100153. [PMID: 34808192 PMCID: PMC8953663 DOI: 10.1016/j.jlr.2021.100153] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 10/26/2021] [Accepted: 11/16/2021] [Indexed: 12/18/2022] Open
Abstract
We previously reported that adding a concentrate of transgenic tomatoes expressing the apoA-I mimetic peptide 6F (Tg6F) to a Western diet (WD) ameliorated systemic inflammation. To determine the mechanism(s) responsible for these observations, Ldlr−/− mice were fed chow, a WD, or WD plus Tg6F. We found that a WD altered the taxonomic composition of bacteria in jejunum mucus. For example, Akkermansia muciniphila virtually disappeared, while overall bacteria numbers and lipopolysaccharide (LPS) levels increased. In addition, gut permeability increased, as did the content of reactive oxygen species and oxidized phospholipids in jejunum mucus in WD-fed mice. Moreover, gene expression in the jejunum decreased for multiple peptides and proteins that are secreted into the mucous layer of the jejunum that act to limit bacteria numbers and their interaction with enterocytes including regenerating islet-derived proteins, defensins, mucin 2, surfactant A, and apoA-I. Following WD, gene expression also decreased for Il36γ, Il23, and Il22, cytokines critical for antimicrobial activity. WD decreased expression of both Atoh1 and Gfi1, genes required for the formation of goblet and Paneth cells, and immunohistochemistry revealed decreased numbers of goblet and Paneth cells. Adding Tg6F ameliorated these WD-mediated changes. Adding oxidized phospholipids ex vivo to the jejunum from mice fed a chow diet reproduced the changes in gene expression in vivo that occurred when the mice were fed WD and were prevented with addition of 6F peptide. We conclude that Tg6F ameliorates the WD-mediated increase in oxidized phospholipids that cause changes in jejunum mucus, which induce dysbiosis and systemic inflammation.
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Affiliation(s)
- Pallavi Mukherjee
- Division of Cardiology, Department of Medicine, Los Angeles, CA, USA
| | | | - Victor Grijalva
- Division of Cardiology, Department of Medicine, Los Angeles, CA, USA
| | - Nasrin Dorreh
- Division of Cardiology, Department of Medicine, Los Angeles, CA, USA
| | - Venu Lagishetty
- The Vatche and Tamar Manoukian Division of Digestive Diseases, Los Angeles, CA, USA; UCLA Microbiome Center, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Jonathan P Jacobs
- The Vatche and Tamar Manoukian Division of Digestive Diseases, Los Angeles, CA, USA; UCLA Microbiome Center, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; The Division of Gastroenterology, Hepatology and Parenteral Nutrition, Veterans Administration Greater Los Angeles Healthcare System Los Angeles, Los Angeles, CA, USA
| | | | - Thomas Vallim
- Division of Cardiology, Department of Medicine, Los Angeles, CA, USA; Department of Biological Chemistry, Los Angeles, CA, USA
| | - Julia J Mack
- Division of Cardiology, Department of Medicine, Los Angeles, CA, USA
| | - Mohamad Navab
- Division of Cardiology, Department of Medicine, Los Angeles, CA, USA
| | - Srinivasa T Reddy
- Division of Cardiology, Department of Medicine, Los Angeles, CA, USA; Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
| | - Alan M Fogelman
- Division of Cardiology, Department of Medicine, Los Angeles, CA, USA
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Zhou H, Yuan Y, Wang H, Xiang W, Li S, Zheng H, Wen Y, Ming Y, Chen L, Zhou J. Gut Microbiota: A Potential Target for Cancer Interventions. Cancer Manag Res 2021; 13:8281-8296. [PMID: 34764691 PMCID: PMC8572730 DOI: 10.2147/cmar.s328249] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 10/19/2021] [Indexed: 12/12/2022] Open
Abstract
The gut microbiota plays a crucial role in many physiological processes in the human body. Dysbiosis can disrupt the intestinal barrier and alter metabolism and immune responses, leading to the development of diseases. Over the past few decades, evidence has accumulated linking changes in the composition of the gut microbiota to dozens of seemingly unrelated conditions, including cancer. Overall, the gut microbiota mainly affects the occurrence and development of cancer by damaging host DNA, forming and maintaining a pro-inflammatory environment, and affecting host immune responses. In addition, the gut microbiota can also affect the efficacy and toxicity of chemotherapy, radiotherapy, and immunotherapy. Scientists attempt to improve the efficacy and decrease the toxicity of these treatment modalities by fine-tuning the gut microbiota. The aim of this review is to assist researchers and clinicians in developing new strategies for the detection and treatment of tumors by providing the latest information on the intestinal microbiome and cancer, as well as exploring potential application prospects and mechanisms of action.
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Affiliation(s)
- Hu Zhou
- Department of Neurosurgery, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, People's Republic of China.,Sichuan Clinical Research Center for Neurosurgery, Luzhou, Sichuan, People's Republic of China
| | - Yuan Yuan
- Department of Neurosurgery, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, People's Republic of China.,Sichuan Clinical Research Center for Neurosurgery, Luzhou, Sichuan, People's Republic of China.,Department of Operation and Anaesthesia, Yibin First People's Hospital, Yibin, Sichuan, People's Republic of China
| | - Haorun Wang
- Department of Neurosurgery, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, People's Republic of China.,Sichuan Clinical Research Center for Neurosurgery, Luzhou, Sichuan, People's Republic of China
| | - Wei Xiang
- Department of Neurosurgery, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, People's Republic of China.,Sichuan Clinical Research Center for Neurosurgery, Luzhou, Sichuan, People's Republic of China
| | - Shenjie Li
- Department of Neurosurgery, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, People's Republic of China.,Sichuan Clinical Research Center for Neurosurgery, Luzhou, Sichuan, People's Republic of China
| | - Haowen Zheng
- Department of Neurosurgery, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, People's Republic of China.,Sichuan Clinical Research Center for Neurosurgery, Luzhou, Sichuan, People's Republic of China
| | - Yuqi Wen
- Department of Neurosurgery, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, People's Republic of China.,Sichuan Clinical Research Center for Neurosurgery, Luzhou, Sichuan, People's Republic of China
| | - Yang Ming
- Department of Neurosurgery, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, People's Republic of China.,Sichuan Clinical Research Center for Neurosurgery, Luzhou, Sichuan, People's Republic of China
| | - Ligang Chen
- Department of Neurosurgery, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, People's Republic of China.,Sichuan Clinical Research Center for Neurosurgery, Luzhou, Sichuan, People's Republic of China.,Academician (Expert) Workstation of Sichuan Province, Luzhou, Sichuan, People's Republic of China.,Neurological Diseases and Brain Function Laboratory, Luzhou, Sichuan, People's Republic of China
| | - Jie Zhou
- Department of Neurosurgery, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, People's Republic of China.,Sichuan Clinical Research Center for Neurosurgery, Luzhou, Sichuan, People's Republic of China.,Academician (Expert) Workstation of Sichuan Province, Luzhou, Sichuan, People's Republic of China.,Neurological Diseases and Brain Function Laboratory, Luzhou, Sichuan, People's Republic of China
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77
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Won C, Kwon C, Park K, Seo J, Lee T. Electronic Drugs: Spatial and Temporal Medical Treatment of Human Diseases. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2005930. [PMID: 33938022 DOI: 10.1002/adma.202005930] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 11/11/2020] [Indexed: 06/12/2023]
Abstract
Recent advances in diagnostics and medicines emphasize the spatial and temporal aspects of monitoring and treating diseases. However, conventional therapeutics, including oral administration and injection, have difficulties meeting these aspects due to physiological and technological limitations, such as long-term implantation and a narrow therapeutic window. As an innovative approach to overcome these limitations, electronic devices known as electronic drugs (e-drugs) have been developed to monitor real-time body signals and deliver specific treatments to targeted tissues or organs. For example, ingestible and patch-type e-drugs could detect changes in biomarkers at the target sites, including the gastrointestinal (GI) tract and the skin, and deliver therapeutics to enhance healing in a spatiotemporal manner. However, medical treatments often require invasive surgical procedures and implantation of medical equipment for either short or long-term use. Therefore, approaches that could minimize implantation-associated side effects, such as inflammation and scar tissue formation, while maintaining high functionality of e-drugs, are highly needed. Herein, the importance of the spatial and temporal aspects of medical treatment is thoroughly reviewed along with how e-drugs use cutting-edge technological innovations to deal with unresolved medical challenges. Furthermore, diverse uses of e-drugs in clinical applications and the future perspectives of e-drugs are discussed.
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Affiliation(s)
- Chihyeong Won
- Nanobio Device Laboratory, School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Chaebeen Kwon
- Nanobio Device Laboratory, School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Kijun Park
- Biological Interfaces and Sensor Systems Laboratory, School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Jungmok Seo
- Biological Interfaces and Sensor Systems Laboratory, School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Taeyoon Lee
- Nanobio Device Laboratory, School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
- Center for BioMicrosystems, Brain Science Institute, Korea Institute of Science and Technology (KIST), 5, Hwarang-ro 14-gil, Seongbuk-gu, Seoul, 02792, Republic of Korea
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78
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Gregory AL, Pensinger DA, Hryckowian AJ. A short chain fatty acid-centric view of Clostridioides difficile pathogenesis. PLoS Pathog 2021; 17:e1009959. [PMID: 34673840 PMCID: PMC8530303 DOI: 10.1371/journal.ppat.1009959] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Clostridioides difficile is an opportunistic diarrheal pathogen responsible for significant morbidity and mortality worldwide. A disrupted (dysbiotic) gut microbiome, commonly engendered by antibiotic treatment, is the primary risk factor for C. difficile infection, highlighting that C. difficile–microbiome interactions are critical for determining the fitness of this pathogen. Here, we review short chain fatty acids (SCFAs): a major class of metabolites present in the gut, their production by the gut microbiome, and their impacts on the biology of the host and of C. difficile. We use these observations to illustrate a conceptual model whereby C. difficile senses and responds to SCFAs as a marker of a healthy gut and tunes its virulence accordingly in order to maintain dysbiosis. Future work to learn the molecular mechanisms and genetic circuitry underlying the relationships between C. difficile and SCFAs will help to identify precision approaches, distinct from antibiotics and fecal transplant, for mitigating disease caused by C. difficile and will inform similar investigations into other gastrointestinal pathogens.
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Affiliation(s)
- Anna L. Gregory
- Department of Medicine, University of Wisconsin School of Medicine & Public Health, Madison, Wisconsin, United States of America
- Department of Medical Microbiology and Immunology, University of Wisconsin School of Medicine & Public Health, Madison, Wisconsin, United States of America
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Daniel A. Pensinger
- Department of Medicine, University of Wisconsin School of Medicine & Public Health, Madison, Wisconsin, United States of America
- Department of Medical Microbiology and Immunology, University of Wisconsin School of Medicine & Public Health, Madison, Wisconsin, United States of America
| | - Andrew J. Hryckowian
- Department of Medicine, University of Wisconsin School of Medicine & Public Health, Madison, Wisconsin, United States of America
- Department of Medical Microbiology and Immunology, University of Wisconsin School of Medicine & Public Health, Madison, Wisconsin, United States of America
- * E-mail:
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79
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Analysis of six tonB gene homologs in Bacteroides fragilis revealed that tonB3 is essential for survival in experimental intestinal colonization and intra-abdominal infection. Infect Immun 2021; 90:e0046921. [PMID: 34662212 DOI: 10.1128/iai.00469-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The opportunistic, anaerobic pathogen and commensal of the human large intestinal tract, Bacteroides fragilis strain 638R, contains six predicted TonB proteins, termed TonB1-6, four ExbBs orthologs, ExbB1-4, and five ExbDs orthologs, ExbD1-5. The inner membrane TonB/ExbB/ExbD complex harvests energy from the proton motive force (Δp) and the TonB C-terminal domain interacts with and transduces energy to outer membrane TonB-dependent transporters (TBDTs). However, TonB's role in activating nearly one hundred TBDTs for nutrient acquisition in B. fragilis during intestinal colonization and extraintestinal infection has not been established. In this study, we show that growth was abolished in the ΔtonB3 mutant when heme, vitamin B12, Fe(III)-ferrichrome, starch, mucin-glycans, or N-linked glycans were used as a substrate for growth in vitro. Genetic complementation of the ΔtonB3 mutant with the tonB3 gene restored growth on these substrates. The ΔtonB1, ΔtonB2, ΔtonB4, ΔtonB5, and ΔtonB6 single mutants did not show a growth defect. This indicates that there was no functional compensation for the lack of TonB3, and it demonstrates that TonB3, alone, drives the TBDTs involved in the transport of essential nutrients. The ΔtonB3 mutant had a severe growth defect in a mouse model of intestinal colonization compared to the parent strain. This intestinal growth defect was enhanced in the ΔtonB3 ΔtonB6 double mutant strain which completely lost its ability to colonize the mouse intestinal tract compared to the parent strain. The ΔtonB1, ΔtonB2, ΔtonB4, and ΔtonB5 mutants did not significantly affect intestinal colonization. Moreover, the survival of the ΔtonB3 mutant strain was completely eradicated in a rat model of intra-abdominal infection. Taken together, these findings show that TonB3 was essential for survival in vivo. The genetic organization of tonB1, tonB2, tonB4, tonB5, and tonB6 gene orthologs indicates that they may interact with periplasmic and nonreceptor outer membrane proteins, but the physiological relevance of this has not been defined. Because anaerobic fermentation metabolism yields a lower Δp than aerobic respiration and B. fragilis has a reduced redox state in its periplasmic space - in contrast to an oxidative environment in aerobes - it remains to be determined if the diverse system of TonB/ExbB/ExbD orthologs encoded by B. fragilis have an increased sensitivity to PMF (relative to aerobic bacteria) to allow for the harvesting of energy under anaerobic conditions.
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80
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Wernke KM, Tirla A, Xue M, Surovtseva YV, Menges FS, Herzon SB. Probing Microbiome Genotoxicity: A Stable Colibactin Provides Insight into Structure-Activity Relationships and Facilitates Mechanism of Action Studies. J Am Chem Soc 2021; 143:15824-15833. [PMID: 34524796 DOI: 10.1021/jacs.1c07559] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Colibactin is a genotoxic metabolite produced by commensal-pathogenic members of the human microbiome that possess the clb (aka pks) biosynthetic gene cluster. clb+ bacteria induce tumorigenesis in models of intestinal inflammation and have been causally linked to oncogenesis in humans. While colibactin is believed underlie these effects, it has not been possible to study the molecule directly due to its instability. Herein, we report the synthesis and biological studies of colibactin 742 (4), a stable colibactin derivative. We show that colibactin 742 (4) induces DNA interstrand-cross-links, activation of the Fanconi Anemia DNA repair pathway, and G2/M arrest in a manner similar to clb+E. coli. The linear precursor 9, which mimics the biosynthetic precursor to colibactin, also recapitulates the bacterial phenotype. In the course of this work, we discovered a novel cyclization pathway that was previously undetected in MS-based studies of colibactin, suggesting a refinement to the natural product structure and its mode of DNA binding. Colibactin 742 (4) and its precursor 9 will allow researchers to study colibactin's genotoxic effects independent of the producing organism for the first time.
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Affiliation(s)
- Kevin M Wernke
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Alina Tirla
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Mengzhao Xue
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Yulia V Surovtseva
- Yale Center for Molecular Discovery, Yale University, West Haven, Connecticut 06516, United States
| | - Fabian S Menges
- Chemical and Biophysical Instrumentation Center, Yale University, New Haven, Connecticut 06511, United States
| | - Seth B Herzon
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States.,Department of Pharmacology, Yale School of Medicine, New Haven, Connecticut 06520, United States
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81
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Baleeiro FCF, Ardila MS, Kleinsteuber S, Sträuber H. Effect of Oxygen Contamination on Propionate and Caproate Formation in Anaerobic Fermentation. Front Bioeng Biotechnol 2021; 9:725443. [PMID: 34568301 PMCID: PMC8460912 DOI: 10.3389/fbioe.2021.725443] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 08/19/2021] [Indexed: 01/19/2023] Open
Abstract
Mixed microbial cultures have become a preferred choice of biocatalyst for chain elongation systems due to their ability to convert complex substrates into medium-chain carboxylates. However, the complexity of the effects of process parameters on the microbial metabolic networks is a drawback that makes the task of optimizing product selectivity challenging. Here, we studied the effects of small air contaminations on the microbial community dynamics and the product formation in anaerobic bioreactors fed with lactate, acetate and H2/CO2. Two stirred tank reactors and two bubble column reactors were operated with H2/CO2 gas recirculation for 139 and 116 days, respectively, at pH 6.0 and 32°C with a hydraulic retention time of 14 days. One reactor of each type had periods with air contamination (between 97 ± 28 and 474 ± 33 mL O2 L−1 d−1, lasting from 4 to 32 days), while the control reactors were kept anoxic. During air contamination, production of n-caproate and CH4 was strongly inhibited, whereas no clear effect on n-butyrate production was observed. In a period with detectable O2 concentrations that went up to 18%, facultative anaerobes of the genus Rummeliibacillus became predominant and only n-butyrate was produced. However, at low air contamination rates and with O2 below the detection level, Coriobacteriia and Actinobacteria gained a competitive advantage over Clostridia and Methanobacteria, and propionate production rates increased to 0.8–1.8 mmol L−1 d−1 depending on the reactor (control reactors 0.1–0.8 mmol L−1 d−1). Moreover, i-butyrate production was observed, but only when Methanobacteria abundances were low and, consequently, H2 availability was high. After air contamination stopped completely, production of n-caproate and CH4 recovered, with n-caproate production rates of 1.4–1.8 mmol L−1 d−1 (control 0.7–2.1 mmol L−1 d−1). The results underline the importance of keeping strictly anaerobic conditions in fermenters when consistent n-caproate production is the goal. Beyond that, micro-aeration should be further tested as a controllable process parameter to shape the reactor microbiome. When odd-chain carboxylates are desired, further studies can develop strategies for their targeted production by applying micro-aerobic conditions.
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Affiliation(s)
- Flávio C F Baleeiro
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.,Institute of Process Engineering in Life Science 2, Technical Biology, Karlsruhe Institute of Technology - KIT, Karlsruhe, Germany
| | - Magda S Ardila
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.,Institute of Process Engineering in Life Science 2, Technical Biology, Karlsruhe Institute of Technology - KIT, Karlsruhe, Germany
| | - Sabine Kleinsteuber
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Heike Sträuber
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
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82
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Chen SM, Lin CP, Jan MS. Early Gut Microbiota Changes in Preterm Infants with Bronchopulmonary Dysplasia: A Pilot Case-Control Study. Am J Perinatol 2021; 38:1142-1149. [PMID: 32446254 DOI: 10.1055/s-0040-1710554] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVE Bronchopulmonary dysplasia (BPD) is a complex chronic lung disease that primarily affects premature or critically ill infants. This pilot study investigated early changes in gut microbiota composition in BPD patients and explored the potential risk factors associated with these changes. STUDY DESIGN Preterm infants admitted to our neonatal intensive care unit with a gestational age of 26 to 32 weeks were prospectively surveyed and eligible for stool collection on days 7 and 28 of postnatal age between February 2016 and June 2017. A 16S rRNA sequencing approach was applied to compare the gut microbiota composition between the BPD group and controls. Multiple linear regression analysis was used to identify the predictor variables. RESULTS Eight subjects in the BPD group and 10 subjects in the preterm group were analyzed during the observation period. Actinobacteria, Proteobacteria, Bacteroidetes, and Firmicutes were the four dominant bacteria phyla of intestinal microflora. A significantly lower diversity of gut microbiota was observed in the BPD group compared with the preterm group on day 28 (number of observed operational taxonomic units, p = 0.034; abundance-based coverage estimator, p = 0.022; Shannon index, p = 0.028). Multiple linear regression analysis revealed that high Neonatal Therapeutic Intervention Scoring System score (≧19) at 24 hours was statistically significant in predicting the proportion of aerobic with facultative anaerobic bacteria on day 28 (p = 0.002). CONCLUSION Infants with BPD are prone to develop gut dysbiosis in early life. A higher severity of illness and treatment intensity may indicate a higher risk of disrupting an anaerobic environment in the gut during the first month of life. KEY POINTS · BPD patients are prone to develop gut dysbiosis.. · Lower diversity of gut microbiota.. · Higher risk of disrupting anaerobic environment..
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Affiliation(s)
- Shan-Ming Chen
- Department of Pediatrics, Chung Shan Medical University Hospital, Taichung, Taiwan.,Department of Pediatrics, School of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | - Ching-Pin Lin
- Division of Hepatology and Gastroenterology, Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan.,Institute of Biochemistry, Microbiology and Immunology, Chung Shan Medical University, Taichung, Taiwan
| | - Ming-Shiou Jan
- Institute of Biochemistry, Microbiology and Immunology, Chung Shan Medical University, Taichung, Taiwan.,Immunology Research Center, Chung Shan Medical University, Taichung, Taiwan.,Division of Allergy, Immunology and Rheumatology, Department of Internal Medicine, Chung Shan Medical University, Taichung, Taiwan
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83
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Smallets S, Kendall MM. Post-transcriptional regulation in attaching and effacing pathogens: integration of environmental cues and the impact on gene expression and host interactions. Curr Opin Microbiol 2021; 63:238-243. [PMID: 34450388 DOI: 10.1016/j.mib.2021.08.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 08/04/2021] [Indexed: 11/25/2022]
Abstract
To establish infection, enteric pathogens integrate environmental cues to navigate the gastrointestinal tract and precisely control expression of virulence determinants. Emerging data indicate that post-transcriptional and post-translational gene regulation plays a key role in virulence regulation and pathogen adaptation to the host environment. Here, we highlight recent studies that reveal how physiologically relevant signals initiate post-transcriptional and post-translational regulatory circuits and the impact on virulence gene expression in the attaching and effacing pathogens, enteropathogenic Escherichia coli, enterohemorrhagic E. coli O157:H7, and Citrobacter rodentium.
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Affiliation(s)
- Sarah Smallets
- Department of Biology, University of Virginia, 485 McCormick Rd., Charlottesville, VA, 22904, USA
| | - Melissa M Kendall
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, 1340 Jefferson Park Ave., Charlottesville, VA, 22908, USA.
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84
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Lv H, Huang Y, Wang T, Zhai S, Hou Z, Chen S. Microbial Composition in the Duodenum and Ileum of Yellow Broilers With High and Low Feed Efficiency. Front Microbiol 2021; 12:689653. [PMID: 34385985 PMCID: PMC8353196 DOI: 10.3389/fmicb.2021.689653] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 07/08/2021] [Indexed: 12/26/2022] Open
Abstract
The composition of the gut microbiome plays important roles in digestion, nutrient absorption, and health. Here, we analyzed the microbial composition in the duodenum and ileum of yellow broilers. Chickens were grouped based on feed efficiency (high feed efficiency [HFE] and low feed efficiency [LFE] groups; n = 22 each). Microbial samples from the duodenum and ileum were collected, and 16S rRNA sequencing of the V3–V4 region was performed. The dominant bacteria in the duodenum were from the phyla Firmicutes and Cyanobacteria and the genera Lactobacillus, Faecalibacterium, and Ruminococcus. In the ileum, the phyla Firmicutes and Proteobacteria and the genera Lactobacillus, SMB53 and Enterococcus were predominant. Alpha diversity analysis showed that the microbiota diversity was significantly higher in the duodenum than in the ileum. The structure of the ileal microbiota was similar between groups, and the species richness of the microbiota in the HFE group was significantly higher than that in the LFE group. In the HFE and LFE groups, Firmicutes and Cyanobacteria were negatively correlated, and Lactobacillus had medium to high negative correlations with most other genera. Functional prediction analysis showed that the gluconeogenesis I pathway was the most abundant differential metabolic pathway and was significantly altered in the LFE group. Moreover, although the microbial community structures were similar in the duodenum and ileum, the diversity of the microbial community was significantly higher in the duodenum than in the ileum. Pearson correlation analysis revealed that the phylum Chloroflexi and genera Acinetobacter, Pseudomonas, Bacillus and Neisseria were with coefficients <−0.3 or >0.3. In the ileum, Ruminococcus may be associated with HFE whereas Faecalibacterium may be associated with LFE. These findings may provide valuable foundations for future research on composition and diversity of intestinal microbes and provide insights into the roles of intestinal microbes in improving feed efficiency and the industrial economic benefits of yellow broilers.
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Affiliation(s)
- Huijiao Lv
- National Engineering Laboratory for Animal Breeding and MOA Key Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Yun Huang
- National Engineering Laboratory for Animal Breeding and MOA Key Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Tao Wang
- National Engineering Laboratory for Animal Breeding and MOA Key Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Shangkun Zhai
- National Engineering Laboratory for Animal Breeding and MOA Key Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Zhuocheng Hou
- National Engineering Laboratory for Animal Breeding and MOA Key Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Sirui Chen
- National Engineering Laboratory for Animal Breeding and MOA Key Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, China
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85
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Sun S, Zhu X, Huang X, Murff HJ, Ness RM, Seidner DL, Sorgen AA, Blakley IC, Yu C, Dai Q, Azcarate-Peril MA, Shrubsole MJ, Fodor AA. On the robustness of inference of association with the gut microbiota in stool, rectal swab and mucosal tissue samples. Sci Rep 2021; 11:14828. [PMID: 34290321 PMCID: PMC8295290 DOI: 10.1038/s41598-021-94205-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 06/25/2021] [Indexed: 12/11/2022] Open
Abstract
The gut microbiota plays an important role in human health and disease. Stool, rectal swab and rectal mucosal tissue samples have been used in individual studies to survey the microbial community but the consequences of using these different sample types are not completely understood. In this study, we report differences in stool, rectal swab and rectal mucosal tissue microbial communities with shotgun metagenome sequencing of 1397 stool, swab and mucosal tissue samples from 240 participants. The taxonomic composition of stool and swab samples was distinct, but less different to each other than mucosal tissue samples. Functional profile differences between stool and swab samples are smaller, but mucosal tissue samples remained distinct from the other two types. When the taxonomic and functional profiles were used for inference in association with host phenotypes of age, sex, body mass index (BMI), antibiotics or non-steroidal anti-inflammatory drugs (NSAIDs) use, hypothesis testing using either stool or rectal swab gave broadly significantly correlated results, but inference performed on mucosal tissue samples gave results that were generally less consistent with either stool or swab. Our study represents an important resource for determination of how inference can change for taxa and pathways depending on the choice of where to sample within the human gut.
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Affiliation(s)
- Shan Sun
- grid.266859.60000 0000 8598 2218Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC USA
| | - Xiangzhu Zhu
- grid.412807.80000 0004 1936 9916Department of Medicine, Vanderbilt University Medical Center, Nashville, TN USA
| | - Xiang Huang
- grid.412807.80000 0004 1936 9916Department of Medicine, Vanderbilt University Medical Center, Nashville, TN USA
| | - Harvey J. Murff
- grid.412807.80000 0004 1936 9916Department of Medicine, Vanderbilt University Medical Center, Nashville, TN USA
| | - Reid M. Ness
- grid.412807.80000 0004 1936 9916Department of Medicine, Vanderbilt University Medical Center, Nashville, TN USA
| | - Douglas L. Seidner
- grid.239578.20000 0001 0675 4725Digestive Disease and Surgical Institute, Cleveland Clinic, Cleveland, OH USA
| | - Alicia A. Sorgen
- grid.266859.60000 0000 8598 2218Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC USA
| | - Ivory C. Blakley
- grid.266859.60000 0000 8598 2218Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC USA
| | - Chang Yu
- grid.412807.80000 0004 1936 9916Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN USA
| | - Qi Dai
- grid.412807.80000 0004 1936 9916Department of Medicine, Vanderbilt University Medical Center, Nashville, TN USA
| | - M. Andrea Azcarate-Peril
- grid.410711.20000 0001 1034 1720Department of Medicine and Microbiome Core Facility, School of Medicine, University of North Carolina, Chapel Hill, NC USA
| | - Martha J. Shrubsole
- grid.412807.80000 0004 1936 9916Department of Medicine, Vanderbilt University Medical Center, Nashville, TN USA
| | - Anthony A. Fodor
- grid.266859.60000 0000 8598 2218Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, 9331 Robert D. Snyder Rd, Room 361, Charlotte, NC 28223 USA
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86
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Comprehensive Cultivation of the Swine Gut Microbiome Reveals High Bacterial Diversity and Guides Bacterial Isolation in Pigs. mSystems 2021; 6:e0047721. [PMID: 34282935 PMCID: PMC8407297 DOI: 10.1128/msystems.00477-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Despite the substantial progress made in human gut culturomics, little is known about the culturability of the swine gut microbiota. In this study, we cultured swine gut microbiota using 53 bacterial cultivation methods with different medium and gas combinations from three pigs at four different growth stages. Both culture-dependent (CD; colony mixtures from each method) and culture-independent (CI; original fecal suspensions) samples were subjected to 16S rRNA gene amplicon sequencing. Increasing microbial diversities were observed in both CI and CD samples from successive growth stages. While a total of 378, 482, 565, and 555 bacterial amplicon sequence variants (ASVs) were observed in the CI samples, higher microbial diversities (415, 675, 808, and 823 observed ASVs) were detected using the CD methods at the lactation, nursery, growing, and finishing stages, respectively. We constructed reference culture maps showing the preferred cultivation conditions for specific bacterial taxa and examined the effects of culturing factors such as oxygen, medium, donor pig age, antibiotics, and blood culture preincubation on swine gut microbiota cultivation. We focused on a wide range of beneficial bacteria, chose 1,299 colonies based on the reference map, and Sanger sequenced their 16S rRNA genes. These isolates clustered into 148 different bacterial taxa covering 28 genera. We observed 11, 19, 33, and 25 pairs of cooccurring ASVs in both CD and CI samples at four successive growth stages. This study provides guidance in culturing the swine gut microbiota of interest, which is critical when characterizing their functions in this important animal species. IMPORTANCE The swine gut microbiome has been the focus of many investigations due to the fact that pigs serve as both an excellent biomedical model for human diseases and an important protein source. Substantial progress has been made in swine gut microbiome studies using next-generation sequencing-based culture-independent approaches, but little is known about the culturability of the swine gut microbiota. To understand their roles in swine production, it is critical to culture bacterial strains of interest. In this study, we cultured the gut microbiota from pigs at different growth stages using 53 bacterial cultivation methods with different medium and gas combinations. This study provides evidence that the swine gut microbiota is much more diverse based on a culture-dependent approach than previously known. It provides preliminary guidance for isolating certain bacteria of interest from pigs, which is critical in establishing causal relationships between the gut microbiota and the health status of pigs.
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87
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Aerobic Conditions and Endogenous Reactive Oxygen Species Reduce the Production of Infectious MS2 Phage by Escherichia coli. Viruses 2021; 13:v13071376. [PMID: 34372580 PMCID: PMC8310082 DOI: 10.3390/v13071376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 07/06/2021] [Accepted: 07/12/2021] [Indexed: 11/16/2022] Open
Abstract
Most of the defective/non-infectious enteric phages and viruses that end up in wastewater originate in human feces. Some of the causes of this high level of inactivity at the host stage are unknown. There is a significant gap between how enteric phages are environmentally transmitted and how we might design molecular tools that would only detect infectious ones. Thus, there is a need to explain the low proportion of infectious viral particles once replicated. By analyzing lysis plaque content, we were able to confirm that, under aerobic conditions, Escherichia coli produce low numbers of infectious MS2 phages (I) than the total number of phages indicated by the genome copies (G) with an I/G ratio of around 2%. Anaerobic conditions of replication and ROS inhibition increase the I/G ratio to 8 and 25%, respectively. These data cannot only be explained by variations in the total numbers of MS2 phages produced or in the metabolism of E. coli. We therefore suggest that oxidative damage impacts the molecular replication and assembly of MS2 phages.
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Lay C, Chu CW, Purbojati RW, Acerbi E, Drautz-Moses DI, de Sessions PF, Jie S, Ho E, Kok YJ, Bi X, Chen S, Mak SY, Chua MC, Goh AEN, Chiang WC, Rao R, Chaithongwongwatthana S, Khemapech N, Chongsrisawat V, Martin R, Roeselers G, Ho YS, Hibberd ML, Schuster SC, Knol J. A synbiotic intervention modulates meta-omics signatures of gut redox potential and acidity in elective caesarean born infants. BMC Microbiol 2021; 21:191. [PMID: 34172012 PMCID: PMC8229302 DOI: 10.1186/s12866-021-02230-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 05/17/2021] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND The compromised gut microbiome that results from C-section birth has been hypothesized as a risk factor for the development of non-communicable diseases (NCD). In a double-blind randomized controlled study, 153 infants born by elective C-section received an infant formula supplemented with either synbiotic, prebiotics, or unsupplemented from birth until 4 months old. Vaginally born infants were included as a reference group. Stool samples were collected from day 3 till week 22. Multi-omics were deployed to investigate the impact of mode of delivery and nutrition on the development of the infant gut microbiome, and uncover putative biological mechanisms underlying the role of a compromised microbiome as a risk factor for NCD. RESULTS As early as day 3, infants born vaginally presented a hypoxic and acidic gut environment characterized by an enrichment of strict anaerobes (Bifidobacteriaceae). Infants born by C-section presented the hallmark of a compromised microbiome driven by an enrichment of Enterobacteriaceae. This was associated with meta-omics signatures characteristic of a microbiome adapted to a more oxygen-rich gut environment, enriched with genes associated with reactive oxygen species metabolism and lipopolysaccharide biosynthesis, and depleted in genes involved in the metabolism of milk carbohydrates. The synbiotic formula modulated expression of microbial genes involved in (oligo)saccharide metabolism, which emulates the eco-physiological gut environment observed in vaginally born infants. The resulting hypoxic and acidic milieu prevented the establishment of a compromised microbiome. CONCLUSIONS This study deciphers the putative functional hallmarks of a compromised microbiome acquired during C-section birth, and the impact of nutrition that may counteract disturbed microbiome development. TRIAL REGISTRATION The study was registered in the Dutch Trial Register (Number: 2838 ) on 4th April 2011.
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Affiliation(s)
| | | | - Rikky Wenang Purbojati
- Singapore Centre For Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore
| | - Enzo Acerbi
- Danone Nutricia Research, Singapore, Singapore
| | - Daniela I Drautz-Moses
- Singapore Centre For Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore
| | | | - Song Jie
- Genome Institute of Singapore, Singapore, Singapore
| | - Eliza Ho
- Genome Institute of Singapore, Singapore, Singapore
| | - Yee Jiun Kok
- Bioprocessing Technology Institute, Singapore, Singapore
| | - Xuezhi Bi
- Bioprocessing Technology Institute, Singapore, Singapore
| | - Shuwen Chen
- Bioprocessing Technology Institute, Singapore, Singapore
| | - Shi Ya Mak
- Bioprocessing Technology Institute, Singapore, Singapore
| | - Mei Chien Chua
- KK Women's and Children's Hospital, Singapore, Singapore
| | - Anne E N Goh
- KK Women's and Children's Hospital, Singapore, Singapore
| | | | - Rajeshwar Rao
- KK Women's and Children's Hospital, Singapore, Singapore
| | | | - Nipon Khemapech
- King Chulalongkorn Memorial Hospital, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Voranush Chongsrisawat
- King Chulalongkorn Memorial Hospital, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Rocio Martin
- Danone Nutricia Research, Utrecht, The Netherlands
| | | | - Ying Swan Ho
- Bioprocessing Technology Institute, Singapore, Singapore
| | - Martin L Hibberd
- Genome Institute of Singapore, Singapore, Singapore
- London School of Hygiene and Tropical Medicine, London, UK
| | - Stephan C Schuster
- Singapore Centre For Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore
| | - Jan Knol
- Danone Nutricia Research, Utrecht, The Netherlands.
- Wageningen University, Wageningen, The Netherlands.
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89
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Chikina A, Matic Vignjevic D. At the right time in the right place: How do luminal gradients position the microbiota along the gut? Cells Dev 2021; 168:203712. [PMID: 34174490 DOI: 10.1016/j.cdev.2021.203712] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 06/16/2021] [Accepted: 06/21/2021] [Indexed: 01/02/2023]
Abstract
The gastrointestinal system is highly compartmentalized, where individual segments perform separate tasks to achieve common physiological goals. The gut luminal content, chyme, changes its chemical and physical properties as it passes through different intestinal segments. Together, the chyme composition, mucus, pH and oxygen gradients along the gut create a variety of highly distinct ecological niches that form, maintain and reinforce the symbiosis with the particular microbiota. Hosting different microbiota members at specific locations creates one of the most complex and sophisticated gradient - gradient of the local ecosystems that live and interact with each other, providing advantages and challenges to the host and creating our microbial self. Here, we discuss how intestinal luminal gradients are created and maintained in homeostasis, their role in a correct microbiota positioning, and their change upon inflammation and cancer.
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Affiliation(s)
- Aleksandra Chikina
- Institut Curie, PSL Research University, CNRS UMR 144, F-75005 Paris, France.
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90
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Carlson AL, Xia K, Azcarate-Peril MA, Rosin SP, Fine JP, Mu W, Zopp JB, Kimmel MC, Styner MA, Thompson AL, Propper CB, Knickmeyer RC. Infant gut microbiome composition is associated with non-social fear behavior in a pilot study. Nat Commun 2021; 12:3294. [PMID: 34078892 PMCID: PMC8172562 DOI: 10.1038/s41467-021-23281-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 04/19/2021] [Indexed: 02/04/2023] Open
Abstract
Experimental manipulation of gut microbes in animal models alters fear behavior and relevant neurocircuitry. In humans, the first year of life is a key period for brain development, the emergence of fearfulness, and the establishment of the gut microbiome. Variation in the infant gut microbiome has previously been linked to cognitive development, but its relationship with fear behavior and neurocircuitry is unknown. In this pilot study of 34 infants, we find that 1-year gut microbiome composition (Weighted Unifrac; lower abundance of Bacteroides, increased abundance of Veillonella, Dialister, and Clostridiales) is significantly associated with increased fear behavior during a non-social fear paradigm. Infants with increased richness and reduced evenness of the 1-month microbiome also display increased non-social fear. This study indicates associations of the human infant gut microbiome with fear behavior and possible relationships with fear-related brain structures on the basis of a small cohort. As such, it represents an important step in understanding the role of the gut microbiome in the development of human fear behaviors, but requires further validation with a larger number of participants.
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Affiliation(s)
- Alexander L Carlson
- Frank Porter Graham Child Development Institute, University of North Carolina, Chapel Hill, NC, USA
| | - Kai Xia
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA
| | - M Andrea Azcarate-Peril
- Department of Medicine, University of North Carolina, Chapel Hill, NC, USA
- Microbiome Core Facility, University of North Carolina, Chapel Hill, NC, USA
| | - Samuel P Rosin
- Department of Biostatistics, University of North Carolina, Chapel Hill, NC, USA
| | - Jason P Fine
- Department of Biostatistics, University of North Carolina, Chapel Hill, NC, USA
| | - Wancen Mu
- Department of Biostatistics, University of North Carolina, Chapel Hill, NC, USA
| | - Jared B Zopp
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA
| | - Mary C Kimmel
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA
| | - Martin A Styner
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA
- Department of Computer Science, University of North Carolina, Chapel Hill, NC, USA
| | - Amanda L Thompson
- Department of Anthropology, University of North Carolina, Chapel Hill, NC, USA
- Department of Nutrition, University of North Carolina, Chapel Hill, NC, USA
| | - Cathi B Propper
- Frank Porter Graham Child Development Institute, University of North Carolina, Chapel Hill, NC, USA
| | - Rebecca C Knickmeyer
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA.
- Department of Pediatrics and Human Development, Michigan State University, East Lansing, MI, USA.
- Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, USA.
- C-RAIND Fellow and Co-Director, Michigan State University, East Lansing, MI, USA.
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91
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Adade EE, Al Lakhen K, Lemus AA, Valm AM. Recent progress in analyzing the spatial structure of the human microbiome: distinguishing biogeography and architecture in the oral and gut communities. CURRENT OPINION IN ENDOCRINE AND METABOLIC RESEARCH 2021; 18:275-283. [PMID: 35936977 PMCID: PMC9351436 DOI: 10.1016/j.coemr.2021.04.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Fueled by technological advances in methods for sample collection and preservation in sequencing studies, and in advances in computational analyses of high content image data, the spatial structure of the human microbiome is coming to light. In this mini-review, we summarize recent developments in our understanding of the structure of two human microbiomes: the lower gut and the oral cavity. We focus on only the most recent literature and we make an important distinction between two forms of spatial structure, governed by scale: biogeography and architecture. By segmenting the study of microbiome spatial structure into two categories, we demonstrate the potential to greatly advance our understanding of the mechanistic principles that link structure and function in the microbiome.
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Affiliation(s)
- Emmanuel E. Adade
- Department of Biological Sciences, State University of New York at Albany, Albany, NY 12222 USA
| | - Khalid Al Lakhen
- Department of Biological Sciences, State University of New York at Albany, Albany, NY 12222 USA
| | - Alex A. Lemus
- Department of Biological Sciences, State University of New York at Albany, Albany, NY 12222 USA
| | - Alex M. Valm
- Department of Biological Sciences, State University of New York at Albany, Albany, NY 12222 USA,Corresponding author.
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Early-Life Immune System Maturation in Chickens Using a Synthetic Community of Cultured Gut Bacteria. mSystems 2021; 6:6/3/e01300-20. [PMID: 34006629 PMCID: PMC8269260 DOI: 10.1128/msystems.01300-20] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The gut microbiome is crucial for both maturation of the immune system and colonization resistance against enteric pathogens. Although chicken are important domesticated animals, the impact of their gut microbiome on the immune system is understudied. Therefore, we investigated the effect of microbiome-based interventions on host mucosal immune responses. Increased levels of IgA and IgY were observed in chickens exposed to maternal feces after hatching compared with strict hygienic conditions. This was accompanied by increased gut bacterial diversity as assessed by 16S rRNA gene amplicon sequencing. Cultivation work allowed the establishment of a collection of 43 bacterial species spanning 4 phyla and 19 families, including the first cultured members of 3 novel genera and 4 novel species that were taxonomically described. This resource is available at www.dsmz.de/chibac. A synthetic community consisting of nine phylogenetically diverse and dominant species from this collection was designed and found to be moderately efficient in boosting immunoglobulin levels when provided to chickens early in life. IMPORTANCE The immune system plays a crucial role in sustaining animal health. Its development is markedly influenced by early microbial colonization of the gastrointestinal tract. As chicken are fully dependent on environmental microbes after hatching, extensive hygienic measures in production facilities are detrimental to the microbiota, resulting in low colonization resistance against pathogens. To combat enteric infections, antibiotics are frequently used, which aggravates the issue by altering gut microbiota colonization. Intervention strategies based on cultured gut bacteria are proposed to influence immune responses in chicken.
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93
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Guzmán-Mejía F, Godínez-Victoria M, Vega-Bautista A, Pacheco-Yépez J, Drago-Serrano ME. Intestinal Homeostasis under Stress Siege. Int J Mol Sci 2021; 22:ijms22105095. [PMID: 34065791 PMCID: PMC8150578 DOI: 10.3390/ijms22105095] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 04/28/2021] [Accepted: 04/30/2021] [Indexed: 01/15/2023] Open
Abstract
Intestinal homeostasis encompasses a complex and balanced interplay among a wide array of components that collaborate to maintain gut barrier integrity. The appropriate function of the gut barrier requires the mucus layer, a sticky cushion of mucopolysaccharides that overlays the epithelial cell surface. Mucus plays a critical anti-inflammatory role by preventing direct contact between luminal microbiota and the surface of the epithelial cell monolayer. Moreover, mucus is enriched with pivotal effectors of intestinal immunity, such as immunoglobulin A (IgA). A fragile and delicate equilibrium that supports proper barrier function can be disturbed by stress. The impact of stress upon intestinal homeostasis results from neuroendocrine mediators of the brain-gut axis (BGA), which comprises a nervous branch that includes the enteric nervous system (ENS) and the sympathetic and parasympathetic nervous systems, as well as an endocrine branch of the hypothalamic-pituitary-adrenal axis. This review is the first to discuss the experimental animal models that address the impact of stress on components of intestinal homeostasis, with special emphasis on intestinal mucus and IgA. Basic knowledge from animal models provides the foundations of pharmacologic and immunological interventions to control disturbances associated with conditions that are exacerbated by emotional stress, such as irritable bowel syndrome.
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Affiliation(s)
- Fabiola Guzmán-Mejía
- Departamento de Sistemas Biológicos, Universidad Autónoma Metropolitana Unidad Xochimilco, Calzada del Hueso No. 1100, CP 04960 Mexico City, Mexico; (F.G.-M.); (A.V.-B.)
| | - Marycarmen Godínez-Victoria
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón s/n, CP 11340 Mexico City, Mexico;
- Correspondence: (M.G.-V.); (M.E.D.-S.); Tel.: +52-55-5729-6000 (ext. 62743) (M.G.-V.); +52-55-5483-7000 (ext. 3624) (M.E.D.-S.)
| | - Alan Vega-Bautista
- Departamento de Sistemas Biológicos, Universidad Autónoma Metropolitana Unidad Xochimilco, Calzada del Hueso No. 1100, CP 04960 Mexico City, Mexico; (F.G.-M.); (A.V.-B.)
| | - Judith Pacheco-Yépez
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón s/n, CP 11340 Mexico City, Mexico;
| | - Maria Elisa Drago-Serrano
- Departamento de Sistemas Biológicos, Universidad Autónoma Metropolitana Unidad Xochimilco, Calzada del Hueso No. 1100, CP 04960 Mexico City, Mexico; (F.G.-M.); (A.V.-B.)
- Correspondence: (M.G.-V.); (M.E.D.-S.); Tel.: +52-55-5729-6000 (ext. 62743) (M.G.-V.); +52-55-5483-7000 (ext. 3624) (M.E.D.-S.)
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Guittar J, Koffel T, Shade A, Klausmeier CA, Litchman E. Resource Competition and Host Feedbacks Underlie Regime Shifts in Gut Microbiota. Am Nat 2021; 198:1-12. [PMID: 34143726 DOI: 10.1086/714527] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractThe spread of an enteric pathogen in the human gut depends on many interacting factors, including pathogen exposure, diet, host gut environment, and host microbiota, but how these factors jointly influence infection outcomes remains poorly characterized. Here we develop a model of host-mediated resource competition between mutualistic and pathogenic taxa in the gut that aims to explain why similar hosts, exposed to the same pathogen, can have such different infection outcomes. Our model successfully reproduces several empirically observed phenomena related to transitions between healthy and infected states, including (1) the nonlinear relationship between pathogen inoculum size and infection persistence, (2) the elevated risk of chronic infection during or after treatment with broad-spectrum antibiotics, (3) the resolution of gut dysbiosis with fecal microbiota transplants, and (4) the potential protection from infection conferred by probiotics. We then use the model to explore how host-mediated interventions-namely, shifts in the supply rates of electron donors (e.g., dietary fiber) and respiratory electron acceptors (e.g., oxygen)-can potentially be used to direct gut community assembly. Our study demonstrates how resource competition and ecological feedbacks between the host and the gut microbiota can be critical determinants of human health outcomes. We identify several testable model predictions ready for experimental validation.
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95
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Do Primocolonizing Bacteria Enable Bacteroides thetaiotaomicron Intestinal Colonization Independently of the Capacity To Consume Oxygen? mSphere 2021; 6:6/3/e00232-19. [PMID: 33952662 PMCID: PMC8103986 DOI: 10.1128/msphere.00232-19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Aerobic bacteria are frequent primocolonizers of the human naive intestine. Their generally accepted role is to eliminate oxygen, which would allow colonization by anaerobes that subsequently dominate bacterial gut populations. Aerobic bacteria are frequent primocolonizers of the human naive intestine. Their generally accepted role is to eliminate oxygen, which would allow colonization by anaerobes that subsequently dominate bacterial gut populations. In this hypothesis-based study, we revisited this dogma experimentally in a germfree mouse model as a mimic of the germfree newborn. We varied conditions leading to the establishment of the dominant intestinal anaerobe Bacteroides thetaiotaomicron. Two variables were introduced: Bacteroides inoculum size and preestablishment by bacteria capable or not of consuming oxygen. High Bacteroides inoculum size enabled its primocolonization. At low inocula, we show that bacterial preestablishment was decisive for subsequent Bacteroides colonization. However, even non-oxygen-respiring bacteria, a hemAEscherichia coli mutant and the intestinal obligate anaerobe Clostridium scindens, facilitated Bacteroides establishment. These findings, which are supported by recent reports, revise the long-held assumption that oxygen scavenging is the main role for aerobic primocolonizing bacteria. Instead, we suggest that better survival of aerobic bacteria ex vivo during vectorization between hosts could be a reason for their frequent primocolonization.
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96
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Schmitz-Esser S. The Rumen Epithelial Microbiota: Possible Gatekeepers of the Rumen Epithelium and Its Potential Contributions to Epithelial Barrier Function and Animal Health and Performance. MEAT AND MUSCLE BIOLOGY 2021. [DOI: 10.22175/mmb.11672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Ruminants are characterized by their unique mode of digesting cellulose-rich plant material in their forestomach, the rumen, which is densely populated by diverse microorganisms that are crucial for the breakdown of plant material. Among ruminal microbial communities, the microorganisms in the rumen fluid or attached to feed particles have attracted considerable research interest. However, comparatively less is known about the microorganisms attached to the rumen epithelium. Generally, the tissue lining the gastrointestinal tract serves the dual role of absorbing nutrients while preventing the infiltration of unwanted compounds and molecules as well as microorganisms. The rumen epithelium fulfills critical physiological functions for the ruminant host in energy absorption, metabolism, and nutrient transport. Essential host metabolites, such as short-chain fatty acids, ammonia, urea, and minerals, are exchanged across the rumen wall, thereby exposing the rumen epithelial microbiota to these nutrients. The integrity of the gastrointestinal barrier is central to animal health and productivity. The integrity of the rumen epithelium can be compromised by high ruminal microbial fermentation activity resulting in decreased rumen pH or by stress conditions such as heat stress or feed restriction. It is important to keep in mind that feeding strategies in cattle have changed over the last decades in favor of energy- and nutrient-rich concentrates instead of fiber-rich forages. These dietary shifts support high milk yields and growth rates but raised concerns regarding a possibly compromised rumen function. This paper will provide an overview of the composition of rumen epithelial microbial communities under physiological and disease conditions and will provide insights into the knowledge about the function and in situ activity of rumen epithelial microorganisms and their relevance for animal health and production. Given that an impaired intestinal barrier will negatively affect economically significant phenotypes, a better understanding of rumen wall microbiota is urgently needed.
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97
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Han X, Mslati MA, Davies E, Chen Y, Allaire JM, Vallance BA. Creating a More Perfect Union: Modeling Intestinal Bacteria-Epithelial Interactions Using Organoids. Cell Mol Gastroenterol Hepatol 2021; 12:769-782. [PMID: 33895425 PMCID: PMC8273413 DOI: 10.1016/j.jcmgh.2021.04.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 04/09/2021] [Accepted: 04/12/2021] [Indexed: 02/08/2023]
Abstract
Intestinal organoids have become indispensable tools for many gastrointestinal researchers, advancing their studies of nontransformed intestinal epithelial cells, and their roles in an array of diseases, including inflammatory bowel disease and colon cancer. In many cases. these diseases, as well as many enteric infections, reflect pathogenic interactions between bacteria and the gut epithelium. The complexity of studying this microbe-epithelial interface in vivo has led to significant focus on modeling this cross-talk using organoid models. Considering how quickly the organoid field is advancing, it can be difficult to keep up to date with the latest techniques, as well as their respective strengths and weaknesses. This review addresses the advantages of using organoids derived from adult stem cells and the recently identified differences that biopsy location and patient age can have on organoids and their interactions with microbes. Several approaches to introducing bacteria in a relevant (apical) manner (ie, microinjecting 3-dimensional spheroids, polarity-reversed organoids, and 2-dimensional monolayers) also are addressed, as are the key readouts that can be obtained using these models. Lastly, the potential for new approaches, such as air-liquid interface, to facilitate studying bacterial interactions with important but understudied epithelial subsets such as goblet cells and their products, is evaluated.
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Affiliation(s)
- Xiao Han
- Department of Pediatrics, British Columbia Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Matthias A Mslati
- Department of Pediatrics, British Columbia Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Emily Davies
- Department of Pediatrics, British Columbia Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Yan Chen
- Department of Pediatrics, British Columbia Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Joannie M Allaire
- Department of Pediatrics, British Columbia Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
| | - Bruce A Vallance
- Department of Pediatrics, British Columbia Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
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Riboflavin instability is a key factor underlying the requirement of a gut microbiota for mosquito development. Proc Natl Acad Sci U S A 2021; 118:2101080118. [PMID: 33827929 PMCID: PMC8053949 DOI: 10.1073/pnas.2101080118] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
We previously determined that several diets used to rear Aedes aegypti and other mosquito species support the development of larvae with a gut microbiota but do not support the development of axenic larvae. In contrast, axenic larvae have been shown to develop when fed other diets. To understand the mechanisms underlying this dichotomy, we developed a defined diet that could be manipulated in concert with microbiota composition and environmental conditions. Initial studies showed that axenic larvae could not grow under standard rearing conditions (27 °C, 16-h light: 8-h dark photoperiod) when fed a defined diet but could develop when maintained in darkness. Downstream assays identified riboflavin decay to lumichrome as the key factor that prevented axenic larvae from growing under standard conditions, while gut community members like Escherichia coli rescued development by being able to synthesize riboflavin. Earlier results showed that conventional and gnotobiotic but not axenic larvae exhibit midgut hypoxia under standard rearing conditions, which correlated with activation of several pathways with essential growth functions. In this study, axenic larvae in darkness also exhibited midgut hypoxia and activation of growth signaling but rapidly shifted to midgut normoxia and arrested growth in light, which indicated that gut hypoxia was not due to aerobic respiration by the gut microbiota but did depend on riboflavin that only resident microbes could provide under standard conditions. Overall, our results identify riboflavin provisioning as an essential function for the gut microbiota under most conditions A. aegypti larvae experience in the laboratory and field.
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99
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Benler S, Yutin N, Antipov D, Rayko M, Shmakov S, Gussow AB, Pevzner P, Koonin EV. Thousands of previously unknown phages discovered in whole-community human gut metagenomes. MICROBIOME 2021; 9:78. [PMID: 33781338 PMCID: PMC8008677 DOI: 10.1186/s40168-021-01017-w] [Citation(s) in RCA: 86] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 02/02/2021] [Indexed: 05/07/2023]
Abstract
BACKGROUND Double-stranded DNA bacteriophages (dsDNA phages) play pivotal roles in structuring human gut microbiomes; yet, the gut virome is far from being fully characterized, and additional groups of phages, including highly abundant ones, continue to be discovered by metagenome mining. A multilevel framework for taxonomic classification of viruses was recently adopted, facilitating the classification of phages into evolutionary informative taxonomic units based on hallmark genes. Together with advanced approaches for sequence assembly and powerful methods of sequence analysis, this revised framework offers the opportunity to discover and classify unknown phage taxa in the human gut. RESULTS A search of human gut metagenomes for circular contigs encoding phage hallmark genes resulted in the identification of 3738 apparently complete phage genomes that represent 451 putative genera. Several of these phage genera are only distantly related to previously identified phages and are likely to found new families. Two of the candidate families, "Flandersviridae" and "Quimbyviridae", include some of the most common and abundant members of the human gut virome that infect Bacteroides, Parabacteroides, and Prevotella. The third proposed family, "Gratiaviridae," consists of less abundant phages that are distantly related to the families Autographiviridae, Drexlerviridae, and Chaseviridae. Analysis of CRISPR spacers indicates that phages of all three putative families infect bacteria of the phylum Bacteroidetes. Comparative genomic analysis of the three candidate phage families revealed features without precedent in phage genomes. Some "Quimbyviridae" phages possess Diversity-Generating Retroelements (DGRs) that generate hypervariable target genes nested within defense-related genes, whereas the previously known targets of phage-encoded DGRs are structural genes. Several "Flandersviridae" phages encode enzymes of the isoprenoid pathway, a lipid biosynthesis pathway that so far has not been known to be manipulated by phages. The "Gratiaviridae" phages encode a HipA-family protein kinase and glycosyltransferase, suggesting these phages modify the host cell wall, preventing superinfection by other phages. Hundreds of phages in these three and other families are shown to encode catalases and iron-sequestering enzymes that can be predicted to enhance cellular tolerance to reactive oxygen species. CONCLUSIONS Analysis of phage genomes identified in whole-community human gut metagenomes resulted in the delineation of at least three new candidate families of Caudovirales and revealed diverse putative mechanisms underlying phage-host interactions in the human gut. Addition of these phylogenetically classified, diverse, and distinct phages to public databases will facilitate taxonomic decomposition and functional characterization of human gut viromes. Video abstract.
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Affiliation(s)
- Sean Benler
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, Maryland 20894 USA
| | - Natalya Yutin
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, Maryland 20894 USA
| | - Dmitry Antipov
- Center for Algorithmic Biotechnology, Institute for Translational Biomedicine, St. Petersburg State University, St. Petersburg, 199004 Russia
| | - Mikhail Rayko
- Center for Algorithmic Biotechnology, Institute for Translational Biomedicine, St. Petersburg State University, St. Petersburg, 199004 Russia
| | - Sergey Shmakov
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, Maryland 20894 USA
| | - Ayal B. Gussow
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, Maryland 20894 USA
| | - Pavel Pevzner
- Center for Algorithmic Biotechnology, Institute for Translational Biomedicine, St. Petersburg State University, St. Petersburg, 199004 Russia
- Department of Computer Science and Engineering, University of California, San Diego, La Jolla, CA 92093 USA
| | - Eugene V. Koonin
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, Maryland 20894 USA
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Nguyen J, Pepin DM, Tropini C. Cause or effect? The spatial organization of pathogens and the gut microbiota in disease. Microbes Infect 2021; 23:104815. [PMID: 33775859 DOI: 10.1016/j.micinf.2021.104815] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 02/28/2021] [Accepted: 03/09/2021] [Indexed: 12/20/2022]
Abstract
The human gut hosts a dense and diverse microbial community, spatially organized in multiple scales of structure. Here, we review how microbial organization differs between health and disease. We describe how changes in spatial organization may induce alterations in gut homeostasis, concluding with a future outlook to reveal causality.
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Affiliation(s)
- Jen Nguyen
- Department of Microbiology & Immunology, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada; School of Biomedical Engineering, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
| | - Deanna M Pepin
- Department of Microbiology & Immunology, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
| | - Carolina Tropini
- Department of Microbiology & Immunology, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada; School of Biomedical Engineering, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada; Humans and the Microbiome Program, Canadian Institute for Advanced Research (CIFAR), Toronto, ON, M5G 1M1, Canada.
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