Fig. 5.

DPP-4i promotes a functional shift in the gut microbiome. (a) Cluster analysis of the HFD and HFD_Sit groups based on the fecal metabolites using PCA analysis. The first two principal components (PC1 and PC2) from the PCA are plotted for each sample. The percentage variation in the plotted principal components is marked on the axes. Each spot represents one sample, and each group of mice is indicated by a different color. (b) Heatmap analysis of the fecal metabolite patterns in the HFD and HFD_Sit groups. The heatmap shows the 109 significantly changed metabolites between the two groups. Each column in the heatmap represents one sample, and each row represents one metabolite. The color bar showing green to red indicates the relative content of metabolites. (c) KEGG pathway enrichment analysis based on the changed metabolites. * p < .05, # p < .01, + p < .001, Fisher's exact test with BH correction. (d) The relative content of succinate in the fecal samples of HFD and HFD_Sit mice. (e) GF mice were fed a HFD and administered succinate in drinking water (2.5%) for 6 weeks. Blood glucose concentrations were measured during a GTT after succinate treatment. (f) The AUC for the GTT curves. All mice were fasted for 6 h before detecting blood glucose. a-d, n = 8; e-f, n = 5. Data in d-f are presented as the means ± SEM. * p < .05, *** p < .001, t-test. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)