Potential Associations Between Microbiome and COVID-19

The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has plunged the world into a major crisis. The disease is characterized by strong infectivity, high morbidity, and high mortality. It is still spreading in some countries. Microbiota and their metabolites affect human physiological health and diseases by participating in host digestion and nutrition, promoting metabolic function, and regulating the immune system. Studies have shown that human microecology is associated with many diseases, including COVID-19. In this research, we first reviewed the microbial characteristics of COVID-19 from the aspects of gut microbiome, lung microbime, and oral microbiome. We found that significant changes take place in both the gut microbiome and airway microbiome in patients with COVID-19 and are characterized by an increase in conditional pathogenic bacteria and a decrease in beneficial bacteria. Then, we summarized the possible microecological mechanisms involved in the progression of COVID-19. Intestinal microecological disorders in individuals may be involved in the occurrence and development of COVID-19 in the host through interaction with ACE2, mitochondria, and the lung-gut axis. In addition, fecal bacteria transplantation (FMT), prebiotics, and probiotics may play a positive role in the treatment of COVID-19 and reduce the fatal consequences of the disease.