Fig. 4: Metabolomics pathways changes associated with aGvHD onset.

a Distribution of non-detectable values for each metabolite was assessed in recipients with or without GvHD. The frequency of non-detectable values in both groups was compared for each distribution profile using a Fisher exact test for a 2 × 2 contingency table and colored as follows: green: frequency of non-detectable values non-significantly different between groups; orange: frequency of non-detectable values significantly different between groups with p < 0.05 but not significant after Bonferroni correction for multiple testing. Red area represents the threshold used for filtration of metabolites with more than 50% of non-detectable value. b A total number of 524 metabolites were analyzed for comparison of recipients with or without GvHD. Among them, 14 metabolites were more frequently detected in one group of patients, but none was significant after Bonferroni correction (Supplementary Data 9). To compare the amount of each metabolite between recipients with or without GvHD, 35 metabolites with more than 50% of non-detectable values were discarded for further analysis. c The remaining 489 metabolites were compared with a Student test with Satterwhaite’s correction for unequal variance, followed by a Bonferroni correction. The volcano plot represents the variation of metabolites amount between recipients with GvHD and those without GvHD according to the −log(p value). List of the 41 significant metabolites is available in Supplementary Data 11. d Heatmap representation of the more significant metabolites after Student test after hierarchical clustering of sample. e, f Significant variation of metabolites was confirmed after global comparison of the relative amounts between compounds. Main pathways identified in the previous analysis (i.e. polyamine metabolism, tryptophan metabolism, urea cycle, arginine & proline metabolism, bacterial or fungal, plasmalogen or lysoplasmalogen, and primary or secondary bile acid metabolism) were used to build an undirected graph where each node is a metabolite and two nodes are connected if their ratio is unchanged between the two groups (see Online Methods). The same network was first colored according to the considered sub-pathway (e) and then according to microbial-derived metabolites (red nodes) (f).