The Thrilling Journey of SARS-CoV-2 into the Intestine: From Pathogenesis to Future Clinical Implications

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has a direct impact on the gastrointestinal system, as up to 50% of fecal samples from coronavirus disease 2019 (COVID-19) patients contain detectable viral RNA despite a negative rhino-pharyngeal swab. This finding, together with an intestinal expression of angiotensin conversion enzyme 2 protein, suggests a possible fecal-oral transmission for SARS-CoV-2. Furthermore, gastrointestinal (GI) symptoms are common in COVID-19 patients including watery diarrhea, vomiting—particularly in children—nausea, and abdominal pain. Pathogenesis of SARS-CoV-2 infection presents significant similarities to those of some immune-mediated diseases, such as inflammatory bowel diseases or rheumatoid arthritis, leading to the hypothesis that targeted therapies used for the treatment of immune-mediated disease could be effective to treat (and possibly prevent) the main complications of COVID-19. In this review, we synthesize the present and future impact of SARS-CoV-2 infection on the gastrointestinal system and on gastroenterology practice, hypothesizing a potential role of the “gut-lung axis” and perhaps of the gut and lung microbiota into the interindividual differential susceptibility to COVID-19 19 disease. Finally, we speculate on the reorganization of outpatient gastroenterology services, which need to consider, among other factors, the major psychological impact of strict lockdown measures on the whole population.

Protective Effects of Lactoferrin against SARS-CoV-2 Infection In Vitro

“…Gastrointestinal symptoms can occur in a broad range of SARS-CoV-2 patients and can sometimes precede the respiratory involvement and be the first manifestation of the infection [ 46 ]. Indeed, gut epithelium expresses the ACE2 receptor, recognized by SARS-CoV-2 to enter host cells, where the virus starts to replicate and to elicit immune system activation characterized by pro-inflammatory cytokines and immune cell recruitment [ 47 ]. Possibly, the immune response could lead to a dysbiosis with a propagation of the pro-inflammatory state [ 47 ].…”

“…Indeed, gut epithelium expresses the ACE2 receptor, recognized by SARS-CoV-2 to enter host cells, where the virus starts to replicate and to elicit immune system activation characterized by pro-inflammatory cytokines and immune cell recruitment [ 47 ]. Possibly, the immune response could lead to a dysbiosis with a propagation of the pro-inflammatory state [ 47 ]. Following oral administration, abundant LF remains on the lining of the gastrointestinal tract [ 48 ], and thus it may be plausible that LF could protect host cells against infection by SARS-CoV-2.…”

Implications of SARS‐CoV‐2 infection for neurogastroenterology

“…16 Several other reports described the detection of SARS-CoV-2 RNA in stool samples. 22,24 A comprehensive metaanalysis 25 included 95 studies and 2149 patients. The authors 25 found that 934 patients (43%) had one or more SARS-CoV-2positive sampling sites (stool or anal swab).…”

Examining the persistence of human Coronavirus 229E on fresh produce

“…ACE-2 is abundantly expressed in the epithelium of the respiratory tract as well as the oral cavity, intestine and colon ( Lamers et al, 2020 ; Qian et al, 2020 ). It is evident now that a considerable proportion of COVID-19 patients demonstrate gastrointestinal symptoms including nausea, vomiting, diarrhea, and abdominal pain ( Cheung et al, 2020 ; Zhou et al, 2020 ; Scaldaferri et al, 2020 ). SARS-CoV-2 RNA has been detected in more than 50% of patients’ stool specimens ( Wolfel et al, 2020 ; Wang et al, 2020 ; Huang et al, 2020 ; Cha et al, 2020 ), and several studies have confirmed that the virus detected in stool is infectious ( Xiao et al, 2020 ; Zhou et al, 2020 ).…”