reported that in adult patient with COVID-19, fecal IL-18 levels positively correlated with the relative abundance of Peptostreptococcus, Fusobacterium, and Citrobacter, indicating that changes in GM composition might contribute to SARS-CoV-2–induced production of inflammatory cytokines in the intestine (Tao et al., 2020). This evidence concerns the gene IL18 and COVID-19.