IL6 and COVID-19: In the oropharyngeal swabs, Scardovia wiggsiae and Veillonella parvula were enriched in COVID-19 patients who died, and we observed significant positive correlations between the relative abundance of Scardovia wiggsiae with plasma concentrations of IL-6 levels (r = 0.39, P = 0.044), IL-10 (r = 0.45, P = 0.044), LBP (r = 0.42, P = 0.044), and the oropharyngeal swab SARS-CoV-2 viral load (r = 0.28, 0.044; Fig. 7B).