Fig. 5

Altered microbial tryptophan metabolism in MCT-induced HSOS rats. A Bubble chart of metabolite pathway enrichment analysis based on KEGG pathway. The size of the bubble reflected the impact in the topology analysis, and the color of the bubble reflected the -ln P-value of the enrichment analysis. The lighter the color, the smaller the P value, which indicates that the degree of enrichment is more significant. B Volcano plot of the metabolomic analysis. C-J The levels of main bacterial tryptophan derivatives in the gut of the control rats or MCT-induced HSOS rats, including indole-3-acetaldehyde (IAAld, C), indole acetic acid IAA, D, indole-3-propanoic acid E, indole-3-acetamide F, indole G, indole-3-carboxaldehyde H, indole-3-carboxylic acid I and indole-3-methyl acetate J. Data were shown as mean ± SEM. N = 5. *p < 0.05, **p < 0.01, ***p < 0.001. MCT, monocrotaline; HSOS, hepatic sinus obstruction syndrome