Fig. 6

Classification based on species abundance and functional composition for obesity status. A ROC curves for the classification models based on taxonomic (microbial species or vOTUs abundance) and functional profiles (KEGG ortholog abundances) of microbiome respectively. B PROC curves to evaluate the model’s classification performance based on taxonomic and functional profiles of microbiome respectively. C ROC curves for the classification models based on taxonomic (microbial species or vOTUs abundance) and functional profiles (KEGG ortholog abundances) of microbiome in combination. D PROC curves to evaluate the model’s classification performance based on taxonomic and functional profiles of microbiome in combination. E, F Cross-study validation of statistical models trained on bacterial species alone(E), or combination of microbial species, vOTUs and KEGG ortholog abundances(F)