Fig. 4

A Figure histogram of changes in SCFAs in the gut lumen and mucosa of the colon (*p < 0.05 compared with day 0; AC, TC, and DC presented the ascending colon, transverse colon, and descending colon; the number means the days for adding xylitol; day 0 presented the sample before adding xylitol). B Canonical correlation analysis (CCA) between species and short-chain fatty acids ((a) lumen, (b) mucosa. The angle of bacteria and SCFAs less than 90° indicated they are in correlation, but not for more than 90°. The length of the arrow represents the impact on community). C Volcano map of different metabolite production levels in vitro (red dot—significantly up-produced metabolites, green dot—significantly down-produced metabolites, gray dot—the metabolites with no significant difference, Q < 0.05). D Volcano map of different gene expression levels (red dot—significantly upregulated genes, blue dot—significantly downregulated genes, gray dot—the genes with no significant difference, Q < 0.05). E Distribution of xylitol metabolic enzymes in microorganisms before and after xylitol supplementation (EC 1.1.1.14-xylitol dehydrogenase; EC 2.7.1.17-xylokinase; EC 5.1.3.1-xylose phosphate isomerase. Before-AC0, the sample in the ascending colon before adding xylitol was defined as Before; After-AC2, the sample in the ascending colon after adding xylitol for 2 days was defined as After)