Fig. 6

Multi-omics interactions and cognitive impairment in the GNHS. a and b Metagenomic and metabolomic markers for distinguishing participants of the mild group from the normal group using the LASSO models based on metagenomic species, pathways or serum metabolites (a), or the combination of these three kinds of features selected from the separated models mentioned above (b). The x axis denotes the coefficients of the features in each model. c Semi-partial correlation of key metagenomic features selected from the combined LASSO model with serum inflammatory cytokines. The intensity of color represents correlation coefficients. False discovery rate (FDR) was calculated using Benjamini–Hochberg method. d Significant associations among 4 aspects of multi-omics: genera of 16S rRNA gene sequencing, metagenomic pathways, serum metabolites, and brain structure. Spearman correlation was used to calculate pairwise correlations of all the measurements. Network shows significant correlations (FDR < 0.05) between each pair of measurement types. Size of nodes represents the number of connections with others. Orange edge, Spearman correlation coefficient > 0; blue edge, Spearman correlation coefficient < 0. Participants were classified into corresponding degrees of cognitive impairment according to their MMSE scores: ‘Mild’ (score ≤ 25), ‘Questionable’ (score 26–29) and ‘Normal’ (score 30). GNHS Guangzhou Nutrition and Health Study, LASSO least absolute shrinkage and selection operator, GM grey matter, WM white matter, CSF cerebrospinal fluid, L left, R right, Frontal_Sup superior frontal gyrus, dorsolateral, Frontal_Mid middle frontal gyrus, Frontal_Inf_Oper inferior frontal gyrus, opercular part, Frontal_Inf_Tri inferior frontal gyrus, triangular part, Frontal_Inf_Orb inferior frontal gyrus, orbital part