Severe acute respiratory syndrome coronavirus‐2 infection and the gut–liver axis

• Published in: Journal of digestive diseases 2020-12, Vol.21 (12), p.687-695
• Main Authors: Mohandas, Sundhar, Vairappan, Balasubramaniyan
• Format: Article
• Language: English
• Subjects: angiotensin converting enzyme 2; Coronaviridae; Coronaviruses; COVID-19; COVID-19 - complications; Digestive system; Disease transmission; dysbiosis; Dysbiosis - virology; gastrointestinal abnormality; Gastrointestinal Diseases - virology; Gastrointestinal Microbiome; Gastrointestinal tract; hepatic injury; Humans; Infections; Intestinal microflora; Intestine; Liver; Liver - pathology; Liver diseases; Liver Diseases - virology; Microbiota; Severe acute respiratory syndrome coronavirus 2; Virus Shedding
• ISSN: 1751-2972; 1751-2980
• DOI: 10.1111/1751-2980.12951

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. Alongside respiratory disorders, patients with severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) manifest abnormalities along the gut–liver axis. SARS‐CoV‐2 translocation to the gut is associated with enterocyte damage, microbial dysbiosis, intestinal permeability and fecal transmission. SARS‐CoV‐2 may precipitate liver injury through angiotensin converting enzyme 2‐mediated cytopathy, systemic inflammation and drug‐induced or hypoxic hepatitis. Considering gut–liver abnormalities will make it easier to predict disease severity and prevent fatal outcomes in patients with SARS‐CoV‐2.