Is a healthy microbiome responsible for lower mortality in COVID-19?

The novel severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) is the cause of an ongoing pandemic with significant case fatality ratio (CFR) worldwide. Although SARS-CoV-2 primarily causes respiratory infection by binding to ACE2 receptors present on alveolar epithelial cells, studies have been published linking the disease to the small intestine enterocytes and its microbiome. Dysbiosis of microbiome, mainly intestinal and lung, can affect the course of the disease. Environmental factors, such as reduced intake of commensal bacteria from the environment or their products in the diet, play an important role in microbiome formation, which can significantly affect the immune response. In elderly, obese or chronically ill people, the microbiota is often damaged. Therefore, we speculate that a good microbiome may be one of the factors responsible for lower CFR from the coronavirus disease 2019 (COVID-19). An approach using tailored nutrition and supplements known to improve the intestinal microbiota and its immune function might help minimize the impact of the disease at least on people at higher risk from coronavirus.