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1.
Rev Med Virol ; 31(5): 1-13, 2021 09.
Article in English | MEDLINE | ID: covidwho-1574011

ABSTRACT

Coronavirus disease 2019 (Covid-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, is now pandemic. While most Covid-19 patients will experience mild symptoms, a small proportion will develop severe disease, which could be fatal. Clinically, Covid-19 patients manifest fever with dry cough, fatigue and dyspnoea, and in severe cases develop into acute respiratory distress syndrome (ARDS), sepsis and multi-organ failure. These severe patients are characterized by hyperinflammation with highly increased pro-inflammatory cytokines including IL-6, IL-17 and TNF-alpha as well as C-reactive protein, which are accompanied by decreased lymphocyte counts. Clinical evidence supports that gut microbiota dysregulation is common in Covid-19 and plays a key role in the pathogenesis of Covid-19. In this narrative review, we summarize the roles of intestinal dysbiosis in Covid-19 pathogenesis and posit that the associated mechanisms are being mediated by gut bacterial metabolites. Based on this premise, we propose possible clinical implications. Various risk factors could be causal for severe Covid-19, and these include advanced age, concomitant chronic disease, SARS-CoV-2 infection of enterocytes, use of antibiotics and psychological distress. Gut dysbiosis is associated with risk factors and severe Covid-19 due to decreased commensal microbial metabolites, which cause reduced anti-inflammatory mechanisms and chronic low-grade inflammation. The preconditioned immune dysregulation enables SARS-CoV-2 infection to progress to an uncontrolled hyperinflammatory response. Thus, a pre-existing gut microbiota that is diverse and abundant could be beneficial for the prevention of severe Covid-19, and supplementation with commensal microbial metabolites may facilitate and augment the treatment of severe Covid-19.


Subject(s)
Bacteria/metabolism , COVID-19/microbiology , Gastrointestinal Microbiome , Animals , Bacteria/classification , Bacteria/genetics , Bacteria/isolation & purification , COVID-19/genetics , COVID-19/immunology , COVID-19/virology , Cytokines/genetics , Cytokines/immunology , Dysbiosis/genetics , Dysbiosis/immunology , Dysbiosis/microbiology , Dysbiosis/virology , Humans , SARS-CoV-2/genetics , SARS-CoV-2/physiology
2.
Front Cell Infect Microbiol ; 10: 596166, 2020.
Article in English | MEDLINE | ID: covidwho-1574497

ABSTRACT

Viral infections continue to cause considerable morbidity and mortality around the world. Recent rises in these infections are likely due to complex and multifactorial external drivers, including climate change, the increased mobility of people and goods and rapid demographic change to name but a few. In parallel with these external factors, we are gaining a better understanding of the internal factors associated with viral immunity. Increasingly the gastrointestinal (GI) microbiome has been shown to be a significant player in the host immune system, acting as a key regulator of immunity and host defense mechanisms. An increasing body of evidence indicates that disruption of the homeostasis between the GI microbiome and the host immune system can adversely impact viral immunity. This review aims to shed light on our understanding of how host-microbiota interactions shape the immune system, including early life factors, antibiotic exposure, immunosenescence, diet and inflammatory diseases. We also discuss the evidence base for how host commensal organisms and microbiome therapeutics can impact the prevention and/or treatment of viral infections, such as viral gastroenteritis, viral hepatitis, human immunodeficiency virus (HIV), human papilloma virus (HPV), viral upper respiratory tract infections (URTI), influenza and SARS CoV-2. The interplay between the gastrointestinal microbiome, invasive viruses and host physiology is complex and yet to be fully characterized, but increasingly the evidence shows that the microbiome can have an impact on viral disease outcomes. While the current evidence base is informative, further well designed human clinical trials will be needed to fully understand the array of immunological mechanisms underlying this intricate relationship.


Subject(s)
Dysbiosis/virology , Microbiota/immunology , Probiotics/therapeutic use , Virus Diseases/immunology , Virus Diseases/microbiology , Animals , COVID-19/immunology , Dysbiosis/immunology , Gastrointestinal Microbiome/immunology , Host Microbial Interactions , Humans , SARS-CoV-2/isolation & purification , Viral Vaccines/administration & dosage , Viral Vaccines/immunology
3.
Cell Mol Life Sci ; 78(16): 5953-5976, 2021 Aug.
Article in English | MEDLINE | ID: covidwho-1293344

ABSTRACT

SARS-CoV-2 is the virus causing the major pandemic facing the world today. Although, SARS-CoV-2 primarily causes lung infection, a variety of symptoms have proven a systemic impact on the body. SARS-CoV-2 has spread in the community quickly infecting humans from all age, ethnicities and gender. However, fatal outcomes have been linked to specific host factors and co-morbidities such as age, hypertension, immuno-deficiencies, chronic lung diseases or metabolic disorders. A major shift in the microbiome of patients suffering of the coronavirus disease 2019 (COVID-19) have also been observed and is linked to a worst outcome of the disease. As many co-morbidities are already known to be associated with a dysbiosis of the microbiome such as hypertension, diabetes and metabolic disorders. Host factors and microbiome changes are believed to be involved as a network in the acquisition of the infection and the development of the diseases. We will review in detail in this manuscript, the immune response toward SARS-CoV-2 infection as well as the host factors involved in the facilitation and worsening of the infection. We will also address the impact of COVID-19 on the host's microbiome and secondary infection which also worsen the disease.


Subject(s)
COVID-19/immunology , COVID-19/virology , Lung/immunology , Lung/virology , SARS-CoV-2/immunology , Virus Replication/immunology , Animals , Dysbiosis/immunology , Dysbiosis/virology , Humans , Immunity/immunology , Microbiota/immunology , Pandemics
4.
PLoS One ; 16(6): e0253293, 2021.
Article in English | MEDLINE | ID: covidwho-1280625

ABSTRACT

BACKGROUND: Human microbiotas are communities of microorganisms living in symbiosis with humans. They play an important role in the host immune response to respiratory viral infection. However, evidence on the human microbiome and coronavirus disease (COVID-19) relationship is insufficient. The aim of this systematic literature review was to evaluate existing evidence on the association between the microbiome and COVID-19 in humans and summarize these data in the pandemic era. METHODS: We conducted a systematic literature review on the association between the microbiome and COVID-19 in humans by searching PubMed, Embase, and the Cochrane Library, CINAHL, and Web of Science databases for articles in English published up to October 31, 2020. The results were analyzed qualitatively. This study is registered with PROSPERO (CRD42020195982). RESULTS: Of the 543 articles identified by searching databases, 16 in line with the research objectives were eligible for qualitative review: eight sampled the microbiome using stool, four using nasopharyngeal or throat swab, three using bronchoalveolar lavage fluid, and one using lung tissue. Fecal microbiome dysbiosis and increased opportunistic pathogens were reported in COVID-19 patients. Several studies suggested the dysbiosis in the lung microbiome of COVID-19 patients with an abundance of opportunistic pathogens using lower respiratory tract samples. The association between COVID-19 severity and the human microbiome remains uncertain. CONCLUSION: The human fecal and respiratory tract microbiome changed in COVID-19 patients with opportunistic pathogen abundance. Further research to elucidate the effect of alternation of the human microbiome in disease pathogenesis is warranted.


Subject(s)
COVID-19/microbiology , Dysbiosis/microbiology , Microbiota , Nasopharynx/microbiology , Bronchoalveolar Lavage Fluid , Dysbiosis/virology , Feces/microbiology , Gastrointestinal Microbiome , Humans
5.
Int J Food Sci Nutr ; 72(3): 293-299, 2021 May.
Article in English | MEDLINE | ID: covidwho-1169469

ABSTRACT

Coronavirus disease 2019 (COVID-19) has become pandemic very rapidly at the beginning of 2020. In the rush to possible therapeutic options, probiotics administration has been proposed mainly based on indirect observation. Some evidence of COVID-19 effects on intestinal microbiota dysbiosis has been shown and probiotics have been considered for their efficacy in the management of respiratory tract viral infections. These observations could be reinforced by the more and more evident existence of a lung-gut axis, suggesting the modulation of gut microbiota among the approaches to the COVID-19 prevention and treatment. As different possible roles of probiotics in this extremely severe illness have been contemplated, the aim of this work is to collect all the currently available information related to this topic, providing a starting point for future studies focussing on it.


Subject(s)
COVID-19/therapy , Dysbiosis/therapy , Gastrointestinal Microbiome , Probiotics/therapeutic use , COVID-19/complications , Dysbiosis/virology , Humans
6.
Front Cell Infect Microbiol ; 11: 632490, 2021.
Article in English | MEDLINE | ID: covidwho-1156114

ABSTRACT

The novel coronavirus SARS-CoV-2 (causing the disease COVID-19) has caused a highly transmissible and ongoing pandemic worldwide. Due to its rapid development, next-generation sequencing plays vital roles in many aspects. Here, we summarize the current knowledge on the origin and human transmission of SARS-CoV-2 based on NGS analysis. The ACE2 expression levels in various human tissues and relevant cells were compared to provide insights into the mechanism of SAS-CoV-2 infection. Gut microbiota dysbiosis observed by metagenome sequencing and the immunogenetics of COVID-19 patients according to single-cell sequencing analysis were also highlighted. Overall, the application of these sequencing techniques could be meaningful for finding novel intermediate SARS-CoV-2 hosts to block interspecies transmission. This information will further benefit SARS-CoV-2 diagnostic development and new therapeutic target discovery. The extensive application of NGS will provide powerful support for our fight against future public health emergencies.


Subject(s)
COVID-19/epidemiology , High-Throughput Nucleotide Sequencing/methods , SARS-CoV-2/genetics , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , COVID-19/microbiology , COVID-19/transmission , COVID-19/virology , Dysbiosis/virology , Gastrointestinal Microbiome , Humans , Metagenome , Pandemics
7.
Chemotherapy ; 66(1-2): 24-32, 2021.
Article in English | MEDLINE | ID: covidwho-1147336

ABSTRACT

Respiratory and gastrointestinal symptoms are the predominant clinical manifestations of the coronavirus disease 2019 (COVID-19). Infecting intestinal epithelial cells, the severe acute respiratory syndrome coronavirus-2 may impact on host's microbiota and gut inflammation. It is well established that an imbalanced intestinal microbiome can affect pulmonary function, modulating the host immune response ("gut-lung axis"). While effective vaccines and targeted drugs are being tested, alternative pathophysiology-based options to prevent and treat COVID-19 infection must be considered on top of the limited evidence-based therapy currently available. Addressing intestinal dysbiosis with a probiotic supplement may, therefore, be a sensible option to be evaluated, in addition to current best available medical treatments. Herein, we summed up pathophysiologic assumptions and current evidence regarding bacteriotherapy administration in preventing and treating COVID-19 pneumonia.


Subject(s)
COVID-19 , Dysbiosis , Gastrointestinal Microbiome/immunology , Probiotics/pharmacology , COVID-19/immunology , COVID-19/physiopathology , COVID-19/prevention & control , Dietary Supplements , Dysbiosis/therapy , Dysbiosis/virology , Humans , SARS-CoV-2
8.
Biomed Res Int ; 2021: 6670798, 2021.
Article in English | MEDLINE | ID: covidwho-1105550

ABSTRACT

Recently, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiologic agent of coronavirus disease 2019 (COVID-19), has led to a worldwide pandemic with millions of infected patients. Alteration in humans' microbiota was also reported in COVID-19 patients. The alteration in human microbiota may contribute to bacterial or viral infections and affect the immune system. Moreover, human's microbiota can be altered due to SARS-CoV-2 infection, and these microbiota changes can indicate the progression of COVID-19. While current studies focus on the gut microbiota, it seems necessary to pay attention to the lung microbiota in COVID-19. This study is aimed at reviewing respiratory microbiota dysbiosis among COVID-19 patients to encourage further studies on the field for assessment of SARS-CoV-2 and respiratory microbiota interaction.


Subject(s)
COVID-19 , Dysbiosis , Lung , Mycobiome/immunology , SARS-CoV-2/immunology , COVID-19/immunology , COVID-19/microbiology , Dysbiosis/immunology , Dysbiosis/microbiology , Dysbiosis/virology , Gastrointestinal Microbiome/immunology , Humans , Lung/immunology , Lung/microbiology , Lung/virology
9.
Neurogastroenterol Motil ; 33(3): e14104, 2021 03.
Article in English | MEDLINE | ID: covidwho-1085279

ABSTRACT

BACKGROUND: Coronavirus disease 2019 (COVID-19) is associated with gastrointestinal and hepatic manifestation in up to one fifth of patients. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiologic agent of COVID-19, infects gastrointestinal epithelial cells expressing angiotensin-converting enzyme 2 (ACE2) receptors triggering a cascade of events leading to mucosal and systemic inflammation. Symptomatic patients display changes in gut microbiota composition and function which may contribute to intestinal barrier dysfunction and immune activation. Evidence suggests that SARS-CoV-2 infection and related mucosal inflammation impact on the function of the enteric nervous system and the activation of sensory fibers conveying information to the central nervous system, which, may at least in part, contribute symptom generation such as vomiting and diarrhea described in COVID-19. Liver and pancreas dysfunctions have also been described as non-respiratory complications of COVID-19 and add further emphasis to the common view of SARS-CoV-2 infection as a systemic disease with multiorgan involvement. PURPOSE: The aim of this review was to highlight the current knowledge on the pathophysiology of gastrointestinal SARS-CoV-2 infection, including the crosstalk with the gut microbiota, the fecal-oral route of virus transmission, and the potential interaction of the virus with the enteric nervous system. We also review the current available data on gastrointestinal and liver manifestations, management, and outcomes of patients with COVID-19.


Subject(s)
COVID-19/complications , COVID-19/physiopathology , Gastrointestinal Diseases/etiology , Gastrointestinal Diseases/physiopathology , Gastrointestinal Microbiome/physiology , Gastrointestinal Tract/physiopathology , Animals , Diarrhea/etiology , Diarrhea/physiopathology , Diarrhea/virology , Dysbiosis/etiology , Dysbiosis/physiopathology , Dysbiosis/virology , Enteric Nervous System/physiopathology , Enteric Nervous System/virology , Gastrointestinal Diseases/virology , Gastrointestinal Tract/virology , Humans , Liver Diseases/etiology , Liver Diseases/physiopathology , Liver Diseases/virology , Pancreatic Diseases/etiology , Pancreatic Diseases/physiopathology , Pancreatic Diseases/virology
10.
11.
Gut ; 70(4): 698-706, 2021 04.
Article in English | MEDLINE | ID: covidwho-1024254

ABSTRACT

OBJECTIVE: Although COVID-19 is primarily a respiratory illness, there is mounting evidence suggesting that the GI tract is involved in this disease. We investigated whether the gut microbiome is linked to disease severity in patients with COVID-19, and whether perturbations in microbiome composition, if any, resolve with clearance of the SARS-CoV-2 virus. METHODS: In this two-hospital cohort study, we obtained blood, stool and patient records from 100 patients with laboratory-confirmed SARS-CoV-2 infection. Serial stool samples were collected from 27 of the 100 patients up to 30 days after clearance of SARS-CoV-2. Gut microbiome compositions were characterised by shotgun sequencing total DNA extracted from stools. Concentrations of inflammatory cytokines and blood markers were measured from plasma. RESULTS: Gut microbiome composition was significantly altered in patients with COVID-19 compared with non-COVID-19 individuals irrespective of whether patients had received medication (p<0.01). Several gut commensals with known immunomodulatory potential such as Faecalibacterium prausnitzii, Eubacterium rectale and bifidobacteria were underrepresented in patients and remained low in samples collected up to 30 days after disease resolution. Moreover, this perturbed composition exhibited stratification with disease severity concordant with elevated concentrations of inflammatory cytokines and blood markers such as C reactive protein, lactate dehydrogenase, aspartate aminotransferase and gamma-glutamyl transferase. CONCLUSION: Associations between gut microbiota composition, levels of cytokines and inflammatory markers in patients with COVID-19 suggest that the gut microbiome is involved in the magnitude of COVID-19 severity possibly via modulating host immune responses. Furthermore, the gut microbiota dysbiosis after disease resolution could contribute to persistent symptoms, highlighting a need to understand how gut microorganisms are involved in inflammation and COVID-19.


Subject(s)
Bacteria , COVID-19 , Dysbiosis , Gastrointestinal Microbiome/immunology , Gastrointestinal Tract , Immunity , SARS-CoV-2 , Adult , Bacteria/genetics , Bacteria/immunology , Bacteria/isolation & purification , C-Reactive Protein/analysis , COVID-19/blood , COVID-19/diagnosis , COVID-19/epidemiology , COVID-19/immunology , Cytokines/analysis , DNA, Bacterial/isolation & purification , Dysbiosis/epidemiology , Dysbiosis/etiology , Dysbiosis/immunology , Dysbiosis/virology , Female , Gastrointestinal Tract/immunology , Gastrointestinal Tract/microbiology , Gastrointestinal Tract/virology , Hong Kong , Humans , Male , SARS-CoV-2/immunology , SARS-CoV-2/isolation & purification , Severity of Illness Index , Transferases/analysis
12.
ACS Chem Neurosci ; 11(24): 4012-4016, 2020 12 16.
Article in English | MEDLINE | ID: covidwho-983572

ABSTRACT

The current pandemic of coronavirus disease 2019 (COVID-19) has gained increased attention in the neuroscience community, especially taking into account the neuroinvasive potential of its causative agent, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and the impact of its infection on the structure and function of the brain. Apart from the neurotropic properties of SARS-CoV-2, it is likewise important the observation that virus infection may perturb specific cellular processes that are believed to play an important role in the pathogenesis of diverse neurological disorders, particularly in Parkinson's disease (PD). In this scenario, viral infection-induced colon inflammation, gut microbial imbalance, and α-synuclein upregulation are of particular interest with regard to the interplay between the gastrointestinal tract and the central nervous system (microbiome-gut-brain axis). In this Perspective, we present a critical view on the different hypotheses that are recently being raised by neuroscientists about the relationship between SARS-CoV-2 infection and long-lasting neurodegenerative disorders, opening the question of whether COVID-19 might represent a risk factor for the development of PD.


Subject(s)
Dysbiosis/virology , Neurodegenerative Diseases/virology , SARS-CoV-2/pathogenicity , Virus Diseases/virology , Brain/pathology , Brain/virology , Dysbiosis/complications , Gastrointestinal Microbiome/physiology , Humans , Neurodegenerative Diseases/pathology , Virus Diseases/complications , Virus Diseases/pathology
13.
Front Cell Infect Microbiol ; 10: 576551, 2020.
Article in English | MEDLINE | ID: covidwho-979016

ABSTRACT

Infection with the SARS-CoV-2 virus causes cardiopulmonary and vascular complications, ranging in severity. Understanding the pathogenic mechanisms of the novel SARS-CoV2 infection and progression can provide potential novel targets for its prevention and/or treatment. Virus microbiota reciprocal interactions have been studied in a variety of viral infections. For example, the integrity of Coronavirus particles can be disrupted by surfactin, a bacterial surface molecule that targets other viruses, including that of influenza A. In this light, intestinal microbiota likely influences COVID-19 virulence, while from its side SARS-CoV-2 may affect the intestinal microbiome promoting dysbiosis and other deleterious consequences. Hence, the microbiota pre-existing health status and its alterations in the course of SARS-CoV-2 infection, are likely to play an important, still underscored role in determining individual susceptibility and resilience to COVID-19. Indeed, the vast majority of COVID-19 worst clinical conditions and fatalities develop in subjects with specific risk factors such as aging and the presence of one or more comorbidities, which are intriguingly characterized also by unhealthy microbiome status. Moreover, these comorbidities require complex pharmacological regimens known as "polypharmacy" that may further affect microbiota integrity and worsen the resilience to viral infections. This complex situation may represent a further and underestimated risk with regard to COVID-19 clinical burden for the elderly and comorbid people. Here, we discuss the possible biological, physiopathological, and clinical implications of gut microbiota in COVID-19 and the strategies to improve/maintain its healthy status as a simple and adjunctive strategy to reduce COVID-19 virulence and socio-sanitary burden.


Subject(s)
COVID-19/microbiology , Gastrointestinal Microbiome/physiology , Gastrointestinal Tract/microbiology , SARS-CoV-2/physiology , Age Factors , COVID-19/drug therapy , COVID-19/physiopathology , COVID-19/virology , Dysbiosis/microbiology , Dysbiosis/virology , Gastrointestinal Microbiome/drug effects , Gastrointestinal Tract/virology , Humans , Microbial Interactions , Risk Factors , Virulence
14.
J Dig Dis ; 21(12): 687-695, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-955673

ABSTRACT

Patients affected by coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, manifest various gastrointestinal and hepatic abnormalities alongside respiratory disorders. The identification of this virus in the feces of more than 50% of infected individuals indicates the possibility of viral shedding and fecal-to-oral transmission. Preliminary reports have also identified alterations in the intestinal microbiota profile in infected individuals. Moreover, COVID-19 patients manifest various degrees of liver injury characterized by alterations in liver enzymes. Digestive symptoms and liver abnormalities correlate with disease severity, the incidence of critical outcomes and patient's recovery. However, the pathogenic mechanisms behind COVID-19-induced abnormalities in the gut-liver axis seem to be multifactorial in origin. This review compiles current knowledge sourced from preclinical and clinical research and summarizes gastrointestinal and hepatic dysfunctions observed following SARS-CoV-2 infection, and also explores the possible mechanisms generating abnormalities in the gut-liver axis. Furthermore, this review sheds light on possible therapeutic targets against these disorders.


Subject(s)
COVID-19/complications , Dysbiosis/virology , Gastrointestinal Diseases/virology , Gastrointestinal Microbiome , Liver Diseases/virology , Humans , Liver/pathology , Virus Shedding
15.
Virus Res ; 291: 198203, 2021 01 02.
Article in English | MEDLINE | ID: covidwho-885454

ABSTRACT

Infectious diseases related to viruses, as well as bacterial pathogens, abound in all parts of the world, burdening health and economy. Thus, there is a dire need to find new prevention and treatment strategies to improve clinical practices related to viral infections. Human gut contains trillions of bacteria which have regulatory roles in immune development, homeostasis, and body metabolism. Today, it is difficult to find any prominent viral infection that hasn't had any link with the human gut microbiota. In this opinion-based review article, I argued the significance of manipulating human gut microbiota as novel therapeutics through probiotics or FMT in alleviating complexities related to viral infections, and pinpointed bottlenecks involved in this research.


Subject(s)
Microbiota/genetics , Probiotics/therapeutic use , Virus Diseases/therapy , Animals , Dysbiosis/etiology , Dysbiosis/therapy , Dysbiosis/virology , Gastrointestinal Microbiome , Humans , Mice , Microbiota/immunology , Virus Diseases/immunology
16.
Virus Res ; 286: 198103, 2020 09.
Article in English | MEDLINE | ID: covidwho-669613

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has evolved into a major pandemic called coronavirus disease 2019 (COVID-19) that has created unprecedented global health emergencies, and emerged as a serious threat due to its strong ability for human-to-human transmission. The reports indicate the ability of SARS-CoV-2 to affect almost any organ due to the presence of a receptor known as angiotensin converting enzyme 2 (ACE2) across the body. ACE2 receptor is majorly expressed in the brush border of gut enterocytes along with the ciliated cells and alveolar epithelial type II cells in the lungs. The amino acid transport function of ACE2 has been linked to gut microbial ecology in gastrointestinal (GI) tract, thereby suggesting that COVID-19 may, to some level, be linked to the enteric microbiota. The significant number of COVID-19 patients shows extra-pulmonary symptoms in the GI tract. Many subsequent studies revealed viral RNA of SARS-CoV-2 in fecal samples of COVID-19 patients. This presents a new challenge in the diagnosis and control of COVID-19 infection with a caution for proper sanitation and hygiene. Here, we aim to discuss the immunological co-ordination between gut and lungs that facilitates SARS-CoV-2 to infect and multiply in the inflammatory bowel disease (IBD) and non-IBD patients.


Subject(s)
Betacoronavirus/pathogenicity , Coronavirus Infections/immunology , Cytokine Release Syndrome/immunology , Dysbiosis/immunology , Gastrointestinal Tract/immunology , Inflammatory Bowel Diseases/immunology , Lung/immunology , Pneumonia, Viral/immunology , Angiotensin-Converting Enzyme 2 , Antibodies, Monoclonal/therapeutic use , Antiviral Agents/therapeutic use , Betacoronavirus/immunology , COVID-19 , Coronavirus Infections/drug therapy , Coronavirus Infections/microbiology , Coronavirus Infections/virology , Cytokine Release Syndrome/drug therapy , Cytokine Release Syndrome/microbiology , Cytokine Release Syndrome/virology , Cytokines/antagonists & inhibitors , Cytokines/genetics , Cytokines/immunology , Dysbiosis/drug therapy , Dysbiosis/microbiology , Dysbiosis/virology , Gastrointestinal Microbiome/immunology , Gastrointestinal Tract/drug effects , Gastrointestinal Tract/microbiology , Gastrointestinal Tract/virology , Gene Expression , Host-Pathogen Interactions/immunology , Humans , Inflammatory Bowel Diseases/drug therapy , Inflammatory Bowel Diseases/microbiology , Inflammatory Bowel Diseases/virology , Lung/drug effects , Lung/microbiology , Lung/virology , Pandemics , Peptidyl-Dipeptidase A/genetics , Peptidyl-Dipeptidase A/immunology , Pneumonia, Viral/drug therapy , Pneumonia, Viral/microbiology , Pneumonia, Viral/virology , Receptors, Virus/genetics , Receptors, Virus/immunology , SARS-CoV-2
17.
Ageing Res Rev ; 62: 101123, 2020 09.
Article in English | MEDLINE | ID: covidwho-650288

ABSTRACT

Coronavirus disease 19 (COVID-19) is a pandemic condition caused by the new coronavirus SARS-CoV-2. The typical symptoms are fever, cough, shortness of breath, evolving to a clinical picture of pneumonia and, ultimately, death. Nausea and diarrhea are equally frequent, suggesting viral infection or transmission via the gastrointestinal-enteric system. SARS-CoV-2 infects human cells by using angiotensin converting enzyme 2 (ACE2) as a receptor, which is cleaved by transmembrane proteases during host cells infection, thus reducing its activities. ACE2 is a relevant player in the renin-angiotensin system (RAS), counterbalancing the deleterious effects of angiotensin II. Furthermore, intestinal ACE2 functions as a chaperone for the aminoacid transporter B0AT1. It has been suggested that B0AT1/ACE2 complex in the intestinal epithelium regulates gut microbiota (GM) composition and function, with important repercussions on local and systemic immune responses against pathogenic agents, namely virus. Notably, productive infection of SARS-CoV-2 in ACE2+ mature human enterocytes and patients' GM dysbiosis was recently demonstrated. This review outlines the evidence linking abnormal ACE2 functions with the poor outcomes (higher disease severity and mortality rate) in COVID-19 patients with pre-existing age-related comorbidities and addresses a possible role for GM dysbiosis. The article culminates with the therapeutics opportunities based on these pathways.


Subject(s)
Betacoronavirus/metabolism , Coronavirus Infections/microbiology , Dysbiosis/virology , Gastrointestinal Microbiome , Peptidyl-Dipeptidase A/metabolism , Pneumonia, Viral/microbiology , Angiotensin-Converting Enzyme 2 , COVID-19 , Comorbidity , Coronavirus Infections/complications , Coronavirus Infections/enzymology , Coronavirus Infections/therapy , Host-Pathogen Interactions , Humans , Molecular Targeted Therapy , Pandemics , Pneumonia, Viral/complications , Pneumonia, Viral/enzymology , Pneumonia, Viral/therapy , Receptor Cross-Talk , Renin-Angiotensin System , SARS-CoV-2
18.
Gastroenterology ; 159(3): 944-955.e8, 2020 09.
Article in English | MEDLINE | ID: covidwho-324569

ABSTRACT

BACKGROUND & AIMS: Although severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infects gastrointestinal tissues, little is known about the roles of gut commensal microbes in susceptibility to and severity of infection. We investigated changes in fecal microbiomes of patients with SARS-CoV-2 infection during hospitalization and associations with severity and fecal shedding of virus. METHODS: We performed shotgun metagenomic sequencing analyses of fecal samples from 15 patients with Coronavirus Disease 2019 (COVID-19) in Hong Kong, from February 5 through March 17, 2020. Fecal samples were collected 2 or 3 times per week from time of hospitalization until discharge; disease was categorized as mild (no radiographic evidence of pneumonia), moderate (pneumonia was present), severe (respiratory rate ≥30/min, or oxygen saturation ≤93% when breathing ambient air), or critical (respiratory failure requiring mechanical ventilation, shock, or organ failure requiring intensive care). We compared microbiome data with those from 6 subjects with community-acquired pneumonia and 15 healthy individuals (controls). We assessed gut microbiome profiles in association with disease severity and changes in fecal shedding of SARS-CoV-2. RESULTS: Patients with COVID-19 had significant alterations in fecal microbiomes compared with controls, characterized by enrichment of opportunistic pathogens and depletion of beneficial commensals, at time of hospitalization and at all timepoints during hospitalization. Depleted symbionts and gut dysbiosis persisted even after clearance of SARS-CoV-2 (determined from throat swabs) and resolution of respiratory symptoms. The baseline abundance of Coprobacillus, Clostridium ramosum, and Clostridium hathewayi correlated with COVID-19 severity; there was an inverse correlation between abundance of Faecalibacterium prausnitzii (an anti-inflammatory bacterium) and disease severity. Over the course of hospitalization, Bacteroides dorei, Bacteroides thetaiotaomicron, Bacteroides massiliensis, and Bacteroides ovatus, which downregulate expression of angiotensin-converting enzyme 2 (ACE2) in murine gut, correlated inversely with SARS-CoV-2 load in fecal samples from patients. CONCLUSIONS: In a pilot study of 15 patients with COVID-19, we found persistent alterations in the fecal microbiome during the time of hospitalization, compared with controls. Fecal microbiota alterations were associated with fecal levels of SARS-CoV-2 and COVID-19 severity. Strategies to alter the intestinal microbiota might reduce disease severity.


Subject(s)
Betacoronavirus , Coronavirus Infections/microbiology , Dysbiosis/virology , Feces/microbiology , Gastrointestinal Microbiome/genetics , Pneumonia, Viral/microbiology , Adult , Aged , COVID-19 , Female , Gastrointestinal Tract/microbiology , Hong Kong/epidemiology , Hospitalization/statistics & numerical data , Humans , Male , Middle Aged , Pandemics , Pilot Projects , SARS-CoV-2
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