HMOX1 and COVID-19: Introduction. This study centres on how coronavirus disease 2019 (COVID-19) disrupts the intestinal microbiota and amplifies systemic inflammation and evaluates ozone water enemas as a strategy to restore gut microbial balance and activate the SIRT1 (silent information regulator of transcription 1)-Nrf2 (nuclear factor erythroid 2-related factor 2)/HO-1 (heme oxygenase-1) pathway for alleviating post-viral sequelae.