Gut-liver indole metabolism (WP3627)

Homo sapiens

Dietary tryptophane is metabolised by the gut microbiome to indole and IPA which reaches the human blood system. Indole is further metabolized into indoxyl sulfate which also reached the blood.


Egon Willighagen , Kristina Hanspers , Martina Summer-Kutmon , and Eric Weitz


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Homo sapiens



Pathway Ontology

classic metabolic pathway


Label Type Compact URI Comment
indoxyl Metabolite chebi:17840
IPA Metabolite chebi:43580
indole Metabolite chebi:16881
dietarytryptophan Metabolite chebi:27897
indole Metabolite chebi:16881
indole Metabolite chebi:16881
IPA Metabolite chebi:43580
indoxyl sulfate Metabolite chebi:43355
indoxyl sulfate Metabolite chebi:43355
tryptophanase GeneProduct eccode:
CYP2E1 GeneProduct ensembl:ENSG00000130649


  1. Metabolomics analysis reveals large effects of gut microflora on mammalian blood metabolites. Wikoff WR, Anfora AT, Liu J, Schultz PG, Lesley SA, Peters EC, et al. Proc Natl Acad Sci U S A. 2009 Mar 10;106(10):3698–703. PubMed Europe PMC Scholia