About this Research Topic
Background: The emergence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its rapid international spread with ongoing devastating effects, poses a global health emergency. SARS-CoV-2 is likely to continue as a recurrent pandemic threat into the future. SARS-CoV-2, which causes COVID-19 (coronavirus disease-2019) pandemic, is thought to have emerged in China from reservoir host bats into a presumed intermediate species and then into humans.
SARS-CoV-2 invades host cells through host angiotensin-converting enzyme 2 (ACE2) receptors. The virus mainly infects lung epithelial cells and spreads through respiratory droplets but has also been shown to impact the GI tract (GIT), kidneys, and cardiovascular system. Recent studies show that intestinal infection with SARS-CoV-2 may correlate with the dysbiosis of gut microbiota as well as the severity of COVID-19 symptoms. Fecal microbiota is associated with SARS-CoV-2 virus load and COVID-19 severity, and ACE2 regulates the gut microbiota. Moreover, the gut microbiota enhances antiviral immunity and stimulates interferon production. Changes in the intestinal microbiota might impact disease severity. Thus, the microbiome might be an effective tool for prognosis, diagnosis, and treatment of COVID-19. The profile of the gut microbiota could be used as a diagnostic biomarker and therapeutic target for COVID-19.
Since the COVID-19 outbreak, many SARS-CoV-2 viruses of coronavirus have been isolated. Multiple variants of SARS-CoV-2 have been identified in different countries and are circulating globally, such as B.1.1.7 (initially detected in the United Kingdom), B.1.351 (first detected in South Africa), P.1 (initially identified in Brazil), B.1.427 and B.1.429 (first identified in California), and B.1.617 (consists of two mutations on the spike protein of the virus and responsible for the rapid increase of infections in India). These emerging variants have played a role in the increased spread of COVID-19.
Goal: Gastrointestinal (GI) symptoms are present in a substantial proportion of COVID-19 patients. Following infection, COVID-19 patients have been shown to have significantly reduced richness and diversity of gut microbiota; a significantly higher abundance of opportunistic pathogens (e.g., Candia albicans, short-chain fatty acid producing bacteria, and a highly heterogeneous mycobiome configuration); lower abundance of beneficial symbionts; immune deregulation, and delayed SARS- CoV-2 clearance. Recent studies show the correlation between the altered microbiota from fecal samples and the elevated levels of intestinal inflammatory cytokine IL-18 in the serum of COVID-19 patients. Changes in gut microbiota composition might also contribute to SARS-CoV-2-induced cytokine storms.
The goal of this Research Topic is therefore to provide a platform for articles that aim to grow our knowledge base of the relationship between COVID-19 and the human gut microbiome.
Scope: We welcome original research articles, methods, reviews, mini reviews and perspectives on but not limited to the following sub-themes:
1. The mechanisms of how the gut microbiome impacts SARS-CoV-2 viral load, COVID-19 pathogenesis, and COVID-19 severity.
2. Exploring the composition, richness, and diversity of microbiota as well as the inflammation and immune profiles of patients infected with SARS-CoV-2 and different variants.
3. The application of state-of-the-art ‘meta-omics’-related research and image technologies in microbiome and COVID-19, such as metagenomics, transcriptomics, metabolomics, and proteomics.
4. Comparing the microbiota of COVID-19 patients with the monitoring results of SARS-CoV-2 spread in local sewage systems.
Keywords: COVID-19, Microbiome, Severity, Prognosis, Diagnosis, Treatment
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.