Gut microbiota and Covid-19- possible link and implications

• Covid-19 disease show gastrointestinal symptoms in some patients hinting at a role of gut-lung axis. • Gut microbiota diversity and its role in immunity highlighted. • Possible role of gut microbiota in Covid-19 discussed. • Implications of gut dysbiosis in Covid-19 analysed. • Role of diet in strengthening the gut microbiota and in the context of Covid-19 discussed. • Suggestions on therapy and prophylaxis based on gut microbiota in Covid-19. Covid-19 is a major pandemic facing the world today caused by SARS-CoV-2 which has implications on our understanding of infectious diseases. Although, SARS-Cov-2 primarily causes lung infection through binding of ACE2 receptors present on the alveolar epithelial cells, yet it was recently reported that SARS-CoV-2 RNA was found in the faeces of infected patients. Interestingly, the intestinal epithelial cells particularly the enterocytes of the small intestine also express ACE2 receptors. Role of the gut microbiota in influencing lung diseases has been well articulated. It is also known that respiratory virus infection causes perturbations in the gut microbiota. Diet, environmental factors and genetics play an important role in shaping gut microbiota which can influence immunity. Gut microbiota diversity is decreased in old age and Covid-19 has been mainly fatal in elderly patients which again points to the role the gut microbiota may play in this disease. Improving gut microbiota profile by personalized nutrition and supplementation known to improve immunity can be one of the prophylactic ways by which the impact of this disease can be minimized in old people and immune-compromised patients. More trials may be initiated to see the effect of co-supplementation of personalized functional food including prebiotics/probiotics along with current therapies.