Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 14, 2021; 27(14): 1406-1418
Published online Apr 14, 2021. doi: 10.3748/wjg.v27.i14.1406
COVID-19 and the gastrointestinal tract: Source of infection or merely a target of the inflammatory process following SARS-CoV-2 infection?
Jacopo Troisi, Giorgia Venutolo, Meritxell Pujolassos Tanyà, Matteo Delli Carri, Annamaria Landolfi, Alessio Fasano
Jacopo Troisi, Meritxell Pujolassos Tanyà, Matteo Delli Carri, Metabolomics Section, Theoreo srl - Spin-off Company of the University of Salerno, Montecorvino Pugliano 84090, SA, Italy
Jacopo Troisi, Matteo Delli Carri, Department of Chemistry and Biology “A. Zambelli”, University of Salerno, Fisciano 84084, SA, Italy
Jacopo Troisi, Giorgia Venutolo, Alessio Fasano, European Biomedical Research Institute of Salerno, Salerno 84125, SA, Italy
Annamaria Landolfi, Department of Medicine, Surgery and Dentistry “Scuola Medica Salernitana”, University of Salerno, Baronissi 84081, SA, Italy
Alessio Fasano, Mucosal Immunology and Biology Research Center and Center for Celiac Research, Harvard Medical School, Massachusetts Gen Hosp Children, Mucosal Immunology and Biology Research Center, Boston, MA 02114, United States
Author contributions: Troisi J, Venutolo G and Landolfi A collected and analyzed the data; Troisi J, Venutolo G, Pujolassos Tanyà M, Delli Carri M and Fasano A wrote the manuscript; Fasano A and Landolfi A edited the manuscript; All the authors approved the final version.
Conflict-of-interest statement: Authors declare that there are no conflicts of interest.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Jacopo Troisi, MBBS, MSc, Professor, Metabolomics Section, Theoreo srl - Spin-off Company of the University of Salerno, Via degli Ulivi, 3, Montecorvino Pugliano 84090, SA, Italy.
Received: February 1, 2021
Peer-review started: February 1, 2021
First decision: February 27, 2021
Revised: March 13, 2021
Accepted: March 19, 2021
Article in press: March 19, 2021
Published online: April 14, 2021

Gastrointestinal (GI) symptoms have been described in a conspicuous percentage of coronavirus disease 2019 (COVID-19) patients. This clinical evidence is supported by the detection of viral RNA in stool, which also supports the hypothesis of a possible fecal-oral transmission route. The involvement of GI tract in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is corroborated by the theoretical assumption that angiotensin converting enzyme 2, which is a SARS-CoV-2 target receptor, is present along the GI tract. Studies have pointed out that gut dysbiosis may occur in COVID-19 patients, with a possible correlation with disease severity and with complications such as multisystem inflammatory syndrome in children. However, the question to be addressed is whether dysbiosis is a consequence or a contributing cause of SARS-CoV-2 infection. In such a scenario, pharmacological therapies aimed at decreasing GI permeability may be beneficial for COVID-19 patients. Considering the possibility of a fecal-oral transmission route, water and environmental sanitation play a crucial role for COVID-19 containment, especially in developing countries.

Keywords: COVID-19, SARS-CoV-2, Gastrointestinal symptoms, Gut microbiome, Dysbiosis, Zonulin, Fecal-oral transmission

Core Tip: Coronavirus disease 2019 (COVID-19) patients may suffer from gastrointestinal symptoms that are associated with gastrointestinal dysbiosis. Even though the exact role of gut microbiome perturbation as a either a cause or a consequence of the disease is still to be elucidated, pharmacological interventions aimed at containing intestinal permeability may be of support in COVID-19 patients.