Fig. 1

Predicted metabolic pathways of dominant microflora. A. Amino acid metabolism. Synthetic pathways and metabolic pathways were significantly reduced, whereas the valine, leucine, and isoleucine degradation pathways were significantly enhanced in the PD group compared with those in the HD group. B. Glucose metabolism. The tricarboxylic acid cycle was slightly increased, whereas the other metabolic pathways, including those of starch and sucrose metabolism, galactose metabolism, and pentose phosphate, were reduced in the PD group compared with those in the HD group. C. Lipid metabolism. The metabolisms of fatty acid, propionate, butyrate, glyceride, and glycerophospholipid were significantly enhanced, but the fatty acid synthesis pathway was significantly weakened in the PD group compared with those in the HD group. D. Vitamin metabolism. Nicotinate and nicotinamide metabolism (vitamin B3), pantothenic acid and coenzyme A biosynthesis (vitamin B5), one_carbon_pool_by_folate (vitamin B9), thiamine metabolism (vitamin B1), and other B vitamin metabolic pathways in the PD group were significantly weakened compared with those in the HD group