↑ upregulated, ↓ downregulated, compared with the corresponding contrast group. bM: brain samples, group M versus C; bD: brain samples, group D versus M; fM: feces samples, group M versus C; fD: feces samples, group D versus M. The DEMs in form of bold within a certain group are highly correlated in a common regulation profile according to the KEGG pathway based clustering analysis.