Fig. 2

Diversity differences in the gut microbiome. A Rarefaction analysis showed that as the number of fecal samples increased, the number of nonredundant genes approached saturation in the mild (n = 45), follow-up (n = 45), and normal (n = 25) groups. B-D The Chao1 (B), Shannon (C), and Simpson (D) indices of the gut microbiome. E,F The NMDS based on the relevant abundance of the microbiome at the phylum level (E) and genus level (F). G The Shannon index of the gut microbiome in the Hong Kong cohort. “ns” represents no significance. H Phylum-level NMDS analysis of the gut microbiome in the Hong Kong cohort. I The Chao1 and Shannon index of the gut microbiome in the Shanghai cohort. J Phylum-level NMDS analysis of gut microbiota in the Shanghai cohort. The mild group consisted of samples obtained from patients diagnosed with mild COVID-19; the follow-up group consisted of samples obtained from patients at the 3-month follow-up after discharge; and the normal group consisted of normal samples. HKL consisted of samples from follow-up mild COVID-19 patients in the Hong Kong cohort after discharge. HKF consisted of samples obtained from patients diagnosed with mild COVID-19. HKH consisted of normal samples. SHL consisted of samples from mild COVID-19 patients. SHH consisted of normal samples. “ns” represents no significance, “ns” represents no significance, *p < 0.05, **p < 0.01, ***p < 0.001, and ****p < 0.0001 (Student’s t test)