preclinical_heavy
Preclinical evidence exceeds central human evidence. Interpret translational relevance cautiously.
supportedtophigh inflation risk
Tryptophan metabolism
crohn's disease
Tryptophan metabolism has meaningful literature visibility in crohn's disease, but the current evidence mix suggests a substantial risk of overclaiming.
Tryptophan metabolism shows a moderate evidence base in crohn's disease, with multiple central papers and additional supporting literature.
tryptophan_metabolism
Credibility score
45
Human translation
1/5
Reproducibility
5/5
Novelty
2/5
Actionability
2/5
Credibility 45Human translation 1/5Reproducibility 5/5Novelty 2/5Actionability 2/5
Why this scores the way it does
- moderate central evidence base
- dense review literature
- substantial preclinical support
Main caveats
- preclinical evidence outweighs human evidence
- review density exceeds central evidence depth
- retrieval noise or disease-specificity issues may remain
Internal review flags
2 flagsreview_heavy
Review literature is very dense relative to primary central evidence.
Primary central evidence
7 papersInflammation-Induced Mucosal KYNU Expression Identifies Human Ileal Crohn's Disease.
2020Journal of clinical medicine
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
Tryptophan degradation as a systems phenomenon in inflammation - an analysis across 13 chronic inflammatory diseases.
2024EBioMedicine
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
Serum Metabolites Relate to Mucosal and Transmural Inflammation in Paediatric Crohn Disease.
2024Journal of Crohn's & colitis
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
Novel cross-feeding human gut microbes metabolizing tryptophan to indole-3-propionate.
2025Gut microbes
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
Metabolic modeling reveals a multi-level deregulation of host-microbiome metabolic networks in IBD.
2025Nature communications
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
Impact of terminal ileal microbiota dysbiosis and tryptophan metabolism alterations on mental disorders in patients with Crohn's disease.
2025BMC gastroenterology
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
Pathobiont-triggered induction of goblet cell response drives regional susceptibility to inflammatory bowel disease.
2026The Journal of clinical investigation
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
Supporting primary evidence
1 papersEnhanced mucosal mitochondrial function corrects dysbiosis and OXPHOS metabolism in IBD.
2024bioRxiv : the preprint server for biology
Relevant preprint retained as supporting evidence, not central evidence.
Preclinical supporting evidence
22 papersCARD9 impacts colitis by altering gut microbiota metabolism of tryptophan into aryl hydrocarbon receptor ligands.
2016Nature medicine
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Indoleacrylic Acid Produced by Commensal Peptostreptococcus Species Suppresses Inflammation.
2017Cell host & microbe
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Increased Tryptophan Metabolism Is Associated With Activity of Inflammatory Bowel Diseases.
2017Gastroenterology
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Palmatine ameliorated murine colitis by suppressing tryptophan metabolism and regulating gut microbiota.
2018Pharmacological research
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Microbial tryptophan metabolites regulate gut barrier function via the aryl hydrocarbon receptor.
2020Proceedings of the National Academy of Sciences of the United States of America
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Deletion of ghrelin alters tryptophan metabolism and exacerbates experimental ulcerative colitis in aged mice.
2022Experimental biology and medicine (Maywood, N.J.)
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Effect of 5-Hydroxytryptophan on Fatigue in Quiescent Inflammatory Bowel Disease: A Randomized Controlled Trial.
2022Gastroenterology
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Rewiring the altered tryptophan metabolism as a novel therapeutic strategy in inflammatory bowel diseases.
2023Gut
Disease-relevant preclinical or model-based paper useful as supporting evidence.
DSS-induced colitis activates the kynurenine pathway in serum and brain by affecting IDO-1 and gut microbiota.
2022Frontiers in immunology
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Pulsatilla chinensis saponins ameliorated murine depression by inhibiting intestinal inflammation mediated IDO1 overexpression and rebalancing tryptophan metabolism.
2023Phytomedicine : international journal of phytotherapy and phytopharmacology
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Wogonin improves colitis by activating the AhR pathway to regulate the plasticity of ILC3/ILC1.
2024Phytomedicine : international journal of phytotherapy and phytopharmacology
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Gut microbiota metabolite indole-3-acetic acid maintains intestinal epithelial homeostasis through mucin sulfation.
2024Gut microbes
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Vinegar-processed Schisandra Chinensis enhanced therapeutic effects on colitis-induced depression through tryptophan metabolism.
2024Phytomedicine : international journal of phytotherapy and phytopharmacology
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Clostridium sporogenes-derived metabolites protect mice against colonic inflammation.
2024Gut microbes
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Impaired Kynurenine Pathway in Inflammatory Bowel Disease.
2024Journal of clinical medicine
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Atractylodes macrocephala Koidz polysaccharide ameliorates DSS-induced colitis in mice by regulating the gut microbiota and tryptophan metabolism.
2025British journal of pharmacology
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Integrating single-cell RNA-Seq and machine learning to dissect tryptophan metabolism in ulcerative colitis.
2024Journal of translational medicine
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Gut microbiota-derived tryptophan metabolites regulated by Wuji Wan to attenuate colitis through AhR signaling activation.
2025Acta pharmaceutica Sinica. B
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Lacticaseibacillus rhamnosus GG-driven remodeling of arginine metabolism mitigates gut barrier dysfunction.
2025American journal of physiology. Gastrointestinal and liver physiology
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Prenatal supplementation with the gut-derived tryptophan metabolite indole-3-propionic acid alleviates colitis susceptibility in maternal immune-activated offspring mice.
2026Journal of advanced research
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Xanthohumol Alleviates Inflammatory Bowel Disease-Associated Osteoporosis via Regulating Gut Microbial Metabolites.
2025Phytotherapy research : PTR
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Akkermansia muciniphila-derived extracellular vesicles alleviate colitis-related cognitive impairment via tryptophan metabolic reprogramming of the gut‒brain axis.
2026Gut microbes
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Review supporting evidence
23 papersTryptophan: A gut microbiota-derived metabolites regulating inflammation.
2017World journal of gastrointestinal pharmacology and therapeutics
Relevant review or meta-analysis for the signal-disease area.
Beneficial actions of microbiota-derived tryptophan metabolites.
2018Neurogastroenterology and motility
Relevant review or meta-analysis for the signal-disease area.
Impact of the Gut Microbiota on Intestinal Immunity Mediated by Tryptophan Metabolism.
2018Frontiers in cellular and infection microbiology
Relevant review or meta-analysis for the signal-disease area.
Gut Microbiota Regulation of Tryptophan Metabolism in Health and Disease.
2018Cell host & microbe
Relevant review or meta-analysis for the signal-disease area.
Glutamatergic Signaling Along The Microbiota-Gut-Brain Axis.
2019International journal of molecular sciences
Relevant review or meta-analysis for the signal-disease area.
Gut microbiota-derived metabolites as key actors in inflammatory bowel disease.
2020Nature reviews. Gastroenterology & hepatology
Relevant review or meta-analysis for the signal-disease area.
Tryptophan Metabolism, Regulatory T Cells, and Inflammatory Bowel Disease: A Mini Review.
2020Mediators of inflammation
Relevant review or meta-analysis for the signal-disease area.
Dietary and Nutritional Approaches to the Management of Chronic Enteropathy in Dogs and Cats.
2021The Veterinary clinics of North America. Small animal practice
Relevant review or meta-analysis for the signal-disease area.
ACE2 and gut amino acid transport.
2020Clinical science (London, England : 1979)
Relevant review or meta-analysis for the signal-disease area.
Impact of Microbial Metabolites on Microbiota-Gut-Brain Axis in Inflammatory Bowel Disease.
2021International journal of molecular sciences
Relevant review or meta-analysis for the signal-disease area.
Tryptophan Metabolism and Gut-Brain Homeostasis.
2021International journal of molecular sciences
Relevant review or meta-analysis for the signal-disease area.
Impact of Bacterial Metabolites on Gut Barrier Function and Host Immunity: A Focus on Bacterial Metabolism and Its Relevance for Intestinal Inflammation.
2021Frontiers in immunology
Relevant review or meta-analysis for the signal-disease area.
Tryptophan-kynurenine metabolism: a link between the gut and brain for depression in inflammatory bowel disease.
2021Journal of neuroinflammation
Relevant review or meta-analysis for the signal-disease area.
Tryptophan-derived serotonin-kynurenine balance in immune activation and intestinal inflammation.
2021FASEB journal : official publication of the Federation of American Societies for Experimental Biology
Relevant review or meta-analysis for the signal-disease area.
Dietary Patterns and Gut Microbiota: The Crucial Actors in Inflammatory Bowel Disease.
2022Advances in nutrition (Bethesda, Md.)
Relevant review or meta-analysis for the signal-disease area.
Disturbances of the Gut Microbiota and Microbiota-Derived Metabolites in Inflammatory Bowel Disease.
2022Nutrients
Relevant review or meta-analysis for the signal-disease area.
The Tryptophan and Kynurenine Pathway Involved in the Development of Immune-Related Diseases.
2023International journal of molecular sciences
Relevant review or meta-analysis for the signal-disease area.
IDO/Kynurenine; novel insight for treatment of inflammatory diseases.
2023Cytokine
Relevant review or meta-analysis for the signal-disease area.
The role of intestinal microbes on intestinal barrier function and host immunity from a metabolite perspective.
2023Frontiers in immunology
Relevant review or meta-analysis for the signal-disease area.
Untargeted faecal metabolomics for the discovery of biomarkers and treatment targets for inflammatory bowel diseases.
2024Gut
Relevant review or meta-analysis for the signal-disease area.
Therapeutic mechanisms of exclusive enteral nutrition in Crohn's disease.
2025Seminars in immunopathology
Relevant review or meta-analysis for the signal-disease area.
Tryptophan metabolism and the intestinal microbiota: Implications for inflammatory bowel disease.
2025Microbiological research
Relevant review or meta-analysis for the signal-disease area.
The gut microbiota and its metabolites: novel therapeutic targets for inflammatory bowel disease.
2025Frontiers in immunology
Relevant review or meta-analysis for the signal-disease area.