Gordian Knot: Gastrointestinal lesions caused by three highly pathogenic coronaviruses from SARS-CoV and MERS-CoV to SARS-CoV-2.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the pathogen of 2019 novel coronavirus disease (COVID-19), is currently spreading around the world. The WHO declared on January 31 that the outbreak of SARS-CoV-2 was a public health emergency. SARS-Cov-2 is a member of highly pathogenic coronavirus group that also consists of severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East Respiratory Syndrome Coronavirus (MERS-CoV). Although respiratory tract lesions were regarded as main manifestation of SARS-Cov-2 infection, gastrointestinal lesions were also reported. Similarly, patients with SARS-CoV and MERS-CoV were also observed. Common gastrointestinal symptoms of patients mainly included diarrhea, vomiting and abdominal pain. Gastrointestinal lesions could be used as basis for early diagnosis of patients, and at the same time, controlling gastrointestinal lesions better facilitated to cut off the route of fecal-oral transmission. Hence, this review summarizes the characteristics and mechanism of gastrointestinal lesions caused by three highly pathogenic human coronavirus infections including SARS-CoV, MERS-CoV, as well as SARS-CoV-2. Furthermore, it is expected to gain experience from gastrointestinal lesions caused by SARS-CoV and MERS-CoV infections in order to be able to better relieve SARS-CoV-2 epidemic. Targetin gut microbiota to regulate the process of SARS-CoV-2 infection should be a concern. Especially, the application of nanotechnology may provide help for further controlling COVID-19.