ACE2 and COVID-19: Our findings revealed a considerable shift in all SARS-CoV-2 variants with the critical sites of the ACE2-B0AT1 complex, with the largest fluctuations occurring in the case of omicron-ACE2-S680-Phosphorylated.These findings contribute to our understanding of metformin's potential mechanism, which will aid in future translational research aimed at treating or mitigating COVID-19 variant breakouts and/or GI symptoms persistence in long-term PASC.