Gut-Lung Axis-A Compass to Navigate Microbiome Landscape in COVID-19

Abstract

The waves of the Coronavirus Disease 2019 (COVID-19) pandemic have disrupted healthcare systems globally, with a staggering number of confirmed cases reaching 593 million and a death toll of six million. While the primary target organ of COVID-19 is the lungs, the novel coronavirus, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) also shows a preference for the intestinal epithelium, which expresses Angiotensin Converting Enzyme 2 (ACE2), a receptor necessary for viral entry into host cells. The composition and abundance of beneficial gut microbiota play a critical role in protecting against severe disease and complications, whereas dysbiosis contribute to systemic inflammation and immune imbalances during SARS-CoV-2 infection. Recent insights into the microbiome have emphasised the importance of the gut-lung axis and the microenvironments of the gut and lungs in the context of COVID-19. These findings offer opportunities for the development of new diagnostic and therapeutic strategies. In this review, the significance of the gut-lung axis, as well as the intestinal and pulmonary microbiota, in COVID-19, were explored with a particular focus on their potential applications