Fig. 5

Metabolomics analysis. A Orthogonal Partial Least Squares-Discriminant Analysis (OPLS-DA) differentiates between healthy controls and Omicron-infected groups.; B Volcano plots reveal Differentially Expressed Metabolites (DEMs) between the two groups; C A heatmap illustrates the expression patterns of DEMs, highlighting significant variations.; D, E Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses show that the identified metabolites are predominantly enriched in tryptophan metabolism, retinal metabolism, and steroid hormone biosynthesis pathways