Fig. 1

Flow chart of experiment. A Population distribution for subjects in the discovery cohort. B Multi-omics analysis of RA with different disease activity levels. C ROC analysis of the external validation cohort in a classification model constructed through a random forest. RA, rheumatoid arthritis; HC, healthy controls; DAS28, Disease Activity Score 28; ITS, Internally Transcribed Spacer; LC–MS, liquid chromatograph mass spectrometer; MADAs, metabolites associated with disease activity; RA-seq, RA sequencing; WES, whole exome sequencing; DEGs, differentially expressed genes; nsSNV, non-synonymous single nucleotide variation; ROC, receiver operating characteristic curves