Fig. 3

Overview of the functional configuration of the ESRD-associated species. a and c Heatmap showing the occurrence of several types of enzymes in ESRD-associated Firmicutes (a) and non-Firmicutes (c) species. Each row represents a KEGG ortholog, while each column represents a species (colored based on their family-level taxonomic assignment). Green and white panels indicate the presence and absence of the enzymes in each species, respectively. Several representative functions and the corresponding species are labeled in the heatmap. b Bar plots showing the occurrence rate of KEGG modules in the ESRD-associated Firmicutes species. Forty KEGG modules that differed in integrity between ESRD-enriched and HC-enriched Firmicutes species (see Additional file 1: Table S10 for details) are shown. The colored bars show the percentage of species that contained complete KEGG modules: red, module present in ESRD-enriched species; blue, module present in HC-enriched species. For a–c, text colored in red and blue denotes enrichment in ESRD patients and healthy controls, respectively. d Boxplot showing the polysaccharide utilization capacity, including animal carbohydrates, plant cell wall carbohydrates, and mucin utilization, of Bacteroidetes species. Nodes represent the species and its colors represent the enrichment of the species: red, enriched in ESRD patients; blue, enriched in healthy controls; gray, not significant. e Boxplot showing the comparison of enzymes involving to polysaccharide utilization in the gut microbiome of ESRD patients and healthy controls. f Occurrence rate of enzymes involved in the biosynthesis of SCFAs, bile acids, and uremic toxins in the ESRD-enriched and HC-enriched species. Red, ESRD-enriched species; blue, HC-enriched species. Fisher’s exact test: *q < 0.05; **q < 0.01; ***q < 0.001. g Schematic diagram depicting the interconnection of ESRD-associated taxa and their functions. Colored triangles denote the taxa that were mostly enriched in ESRD patients (red) or healthy controls (blue), and colored squares denote the functions that were mainly encoded by ESRD-enriched (red) and HC-enriched (blue) species. Connections between the taxa and functions suggest that the functions are likely encoded by the corresponding species