Figure 6: Characterization of the minimal gut genome and metagenome.
From: A human gut microbial gene catalogue established by metagenomic sequencing

a, Projection of the minimal gut genome on the KEGG pathways using the iPath tool38. b, Functional composition of the minimal gut genome and metagenome. Rare and frequent refer to the presence in sequenced eggNOG genomes. c, Estimation of the minimal gut metagenome size. Known orthologous groups (red), known plus unknown orthologous groups (blue) and orthologous groups plus novel gene families (>20 proteins; grey) are shown (see Fig. 2c for definition of box and whisker plot). The inset shows composition of the gut minimal microbiome. Large circle: classification in the minimal metagenome according to orthologous group occurrence in STRING739 bacterial genomes. Common (25%), uncommon (35%) and rare (45%) refer to functions that are present in >50%, <50% but >10%, and <10% of STRING bacteria genomes, respectively. Small circle: composition of the rare orthologous groups. Unknown (80%) have no annotation or are poorly characterized, whereas known bacterial (19%) and phage-related (1%) orthologous groups have functional description.