BGCs with siderophore-like transporters from human gut microbiomes. (A) Concatenated ribosomal protein tree (collapsed to the genus level) for high-quality genomes from the infant and adult gut microbiomes that encode siderophore-like BGCs. On the right are counts of siderophore BGCs from infant gut genomes (blue) and adult gut genomes (red). (B) Gene Cluster Families of BGCs containing known siderophores (bright red) and human microbiome–derived BGCs with siderophore-like transporters. BGCs are connected by similarity to other BGCs in the same gene cluster family, calculated using BiG-SCAPE. (C) Families of siderophore-like BGCs without any similarity to existing known BGCs. BGCs in the network are colored by the taxonomy of the genome of origin and are grouped and labeled by the antiSMASH reported biosynthetic class: for NRPS gene clusters, the adenylation domain specificities are reported.