A peculiar finding from this study [63], once again linking the gut to COVID-19, is that the levels of Bacteroides ovatus, Bacteroides dorei, Bacteroides massiliensis and Bacteroides thetaiotaomicron during hospitalization (the same species that showed to downregulate intestinal expression of ACE-2 in murine gut) were inversely correlated to the load of SARS-CoV-2 in the stool samples from these patients, once again suggesting an implication of the gut microbiota in COVID-19 pathogenesis [63]. Here, ACE2 is linked to COVID-19.