ABSTRACT
BACKGROUND: Since the end of 2019, SARS-CoV-2 has been responsible for the multisystemic hyper-inflammatory disease, namely, COVID-19, as a majorly impactful pandemic. Gastrointestinal (GI) symptoms occurring during and after disease are gaining increasing attention among experts. METHODS: We briefly review and comment on preliminary and recent evidences on prevalence, pathophysiology, and perspective treatment options for GI disturbances during and after COVID-19. RESULTS: Several reports from the literature show a significant portion of COVID-19 patients suffering from GI symptoms both at the early stages of the disease and after the end of it, sometimes for several months, namely "long-COVID-19 " patients, irrespective of vaccination. An unsolved issue regarding COVID-19 is the association between GI symptoms and the outcome of COVID-19 patients. Several studies and metanalyses suggest a worse evolution of COVID-19 in patients presenting with GI symptoms. However, these data have not been agreed. Indeed, only one uniform observation can be found in the literature: patients with chronic liver disease have a worse outcome from COVID-19 infection. Upper and lower GI symptoms have similarities with postinfectious functional dyspepsia (FD) and irritable bowel syndrome (IBS). FD and IBS following infection are recognized as a pathophysiological factor, which is a gut microbial quali- and quantitative unbalance, namely dysbiosis. Furthermore, several preliminary reports and ongoing clinical trials have shown gut microbiota modulation by pre-, pro- and post-biotics to be effective in changing and preventing COVID-19 natural course. CONCLUSION: GI symptoms characterize both long- and non-long-COVID-19 with a potentially significant impact on its natural course. Gut microbiota modulation seems to be a sensible target for disease treatment and/or prevention.