In a multivariate analysis, the Shannon index and CRP were associated with COVID-19 severity, with cut-off values of 2.25 and 96.8 ml/L.RNA viral replication: no associations were found for SARS-CoV-2 replication and COVID-19 severityPatients with lower Shannon diversity displayed SARS-CoV-2 fecal replications4 features:↓ Firmicutes/Bacteroidetes ratio; ↑ Proteobacteria phylum; ↓ butyrate-producing bacteria from Lachnospiraceae family (Roseburia and Lachnospira genera)↓ Actinobacteria essentially Bifidobacteria (Collinsella). This evidence concerns the gene CRP and COVID-19.