Figure 1.

The stool microbiome of hematopoietic cell transplantation (HCT) donors and HCT recipients over time. The height of each colored bar or strip is proportionate to the relative abundance of 1 specific organism identified to the species or genus level. The legend is simplified to the family level for legibility. The coloration is related to the phylum of the organism: Firmicutes, purple/blue (Lachnospiraceae in purple); Proteobacteria, tan; Bacteroides, orange; and Actinobacteria, teal. A. The stool microbiome of 36 healthy HCT donors, demonstrating a typical dominance of Lachnospiracea or Bacteroides, with occasional codominance with Enterobacteraceae. B–E, HCT recipients’ microbiota over time. The x-axis is days relative to transplant. The vertical dashed line depicts the date of neutrophil recovery. For those with severe acute graft-versus-host disease (GVHD) (D and E), the date of GVHD onset is depicted with a black dot on the timeline. C, A patient who underwent a partial colectomy prior to transplant. E, Three HCT recipients who developed both severe and steroid-refractory acute GVHD. The HCT recipients with the most samples were included in this figure; those with fewer samples were omitted in consideration of space. Abbreviations: GVHD, graft-versus-host disease; HCT, hematopoietic cell transplantation.