GVHD patients present distinct postonset predicted PICRUSt pathways. (A) Radar chart representation of PICRUSt predicted functional pathways belonging to 6 main metabolic pathways: carbohydrate degradation, nucleotide biosynthesis, amino acid biosynthesis, antibiotic resistance, vitamin K₂ biosynthesis, and fermentation for GVHD patients post-GVHD onset relative to no-GVHD controls. Axis represents fold change relative to no-GVHD patients. (B) Heat map with hierarchical clustering of statistically significant (FDR P ≤ .05) unique PICRUSt pathways. Figure displays pathways found in a minimum of 5% of samples within all groups. LGI GVHD patients show increased abundance of pathways associated with general antibiotic resistance and vitamin K₂ metabolism with lower abundance of pathways linked to amino acid biosynthesis relative to no-GVHD patients. Lower abundance of pathways specific to butyrate production was also found in LGI patients compared with no-GVHD controls (bold). ∗FDR P ≤ .05; ∗∗FDR P ≤ .01; ∗∗∗FDR P ≤ .001. NS, not significant.