Based on the blood composition RDA, we found that the number of neutrophils, lymphocytes, and platelets were significantly correlated with the microbial composition of patients with COVID‐19 (p < 0.05) (Figure 3G), and based on the immune factor RDA, we found that IL10 and IFN‐γ were significantly correlated with the microbial composition of these patients (p < 0.05) (Figure 3H). The gene discussed is IFNG; the disease is COVID-19.