Some studies address the impact of altered gut microbiota composition on chronic lung disorders and respiratory infections, such as cystic fibrosis, asthma and influenza virus influenza, respectively. Gut bacteria appear to play an important role in modulating the lung immune response and thus in the progression of respiratory disorders such as those caused by covid-19. In addition, SARS-CoV-2 was found in the gastrointestinal tract and in the feces of some patients. In view of the above, the factors that contribute to virulence and evolution of the infection by the new coronavirus, as well as the type and intensity of the immune response triggered, and the role of the gut microbiota in this process, are topics that need to be further elucidated. In this context, considering the urgency in obtaining scientific evidence for decision making in the fight against covid-19, this study evaluated exploratory in vitro and in vivo studies, as well as systematic reviews and meta-analyses about the intestinal microbiota and its role in respiratory viral infection, with a special focus on the new coronavirus.