Fig. 3
Effects of enteral starch on colonic substrate metabolism (n = 8 for SCFAs, pH, and LPS, and n = 6 for metabolome). A Concentrations of SCFAs in colonic digesta (μM/g). The difference between two groups was identified by independent sample T-test. B Colonic digesta pH of two groups of growing goats. The difference between two groups was identified by independent sample T-test. C Absolute concentration of LPS in colonic digesta on log2-transformed concentration correcting for subject. The difference between two groups was identified by independent sample T-test. D OPLS-DA analysis of colonic substrate metabolism. E Heatmap of 15 differential metabolites in colonic digesta (VIP > 1, 0.05 < P < 0.1; both negative and positive modes). The upregulated metabolites are shown in red, whereas the downregulated metabolites are presented in blue. F Microbial KO terms related to the bile acid microbial biotransformation of the HES goats compared with the LES goats. The values are presented as HES/LES fold change. Mann–Whitney U test was carried out for comparing the two groups. EC: 1.1.1.100, K00059, 3-oxoacyl-[acyl-carrier-protein] reductase; EC: 1.1.1.159, K00076, 7-alpha-hydroxysteroid dehydrogenase; EC: 3.5.1.24, K01442, choloylglycine hydrolase; EC: 1.1.1.52, K22604, 3alpha-hydroxycholanate dehydrogenase (NAD +); EC: 1.1.1.392, K22605, 3alpha-hydroxycholanate dehydrogenase (NADP +); EC: 1.1.1.391, K22606, 3beta-hydroxycholanate 3-dehydrogenase (NAD +); ko00120, Primary bile acid biosynthesis; ko00121, Secondary bile acid biosynthesis. G Microbial biotransformation of the bile acids in the colon of HES goats. Red: upregulation. EC: 1.1.1.100, K00059, 3-oxoacyl-[acyl-carrier-protein] reductase; EC: 1.1.1.159, K00076, 7-alpha-hydroxysteroid dehydrogenase; EC: 3.5.1.24, K01442, choloylglycine hydrolase; EC: 1.1.1.52, K22604, 3alpha-hydroxycholanate dehydrogenase (NAD +); EC: 1.1.1.392, K22605, 3alpha-hydroxycholanate dehydrogenase (NADP +); EC: 1.1.1.391, K22606, 3beta-hydroxycholanate 3-dehydrogenase (NAD +). Symbols indicate significance (∗ , P < 0.05; #, 0.05 < P < 0.1)