In a COVID-19 cohort, the depletion of several bacterial species (B. adolescentis, E. rectale and F. prausnitzii, known to play immunomodulatory roles in the human GI system) was linked to increased plasma concentrations of TNF-α, CXCL10, CCL2 and IL-10 [65]. This evidence concerns the gene IL10 and COVID-19.