Fig. 2.

Bubble plot of KEGG pathway enrichment for differential metabolites in serum (a), and differential metabolites in urine (b) of COVID-19 patients. 17 pathways were all down-regulated in serum (a) and they were contributed by lactate and l-Proline, while 5 pathways were all up-regulated in urine (b) that contributed by taurine. There were no up-regulated pathways in serum and down-regulated pathways in urine in COVID-19 patients compared to controls. The point size indicates the count of differential metabolites that involve in the corresponding pathways, and the color indicates the adjusted p value.