preclinical_heavy
Preclinical evidence exceeds central human evidence. Interpret translational relevance cautiously.
fulltophigh inflation risk
Tryptophan metabolism
type 2 diabetes
Tryptophan metabolism has meaningful literature visibility in type 2 diabetes, but the current evidence mix suggests a substantial risk of overclaiming.
Tryptophan metabolism shows a strong literature footprint in type 2 diabetes, with substantial central evidence and broader supporting literature.
tryptophan_metabolism
Credibility score
88
Human translation
2/5
Reproducibility
4/5
Novelty
1/5
Actionability
5/5
Credibility 88Human translation 2/5Reproducibility 4/5Novelty 1/5Actionability 5/5
Why this scores the way it does
- strong central evidence base
- dense review literature
- substantial preclinical support
Main caveats
- preclinical evidence outweighs human evidence
Internal review flags
2 flagssparse_primary_supporting_bucket
Central evidence is high but primary supporting bucket is empty. Classification tiers may still be too coarse.
Primary central evidence
24 papersIncreased Plasma Levels of Xanthurenic and Kynurenic Acids in Type 2 Diabetes.
2015Molecular neurobiology
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
Tryptophan Predicts the Risk for Future Type 2 Diabetes.
2016PloS one
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
Impact of HIV and Type 2 diabetes on Gut Microbiota Diversity, Tryptophan Catabolism and Endothelial Dysfunction.
2018Scientific reports
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
Quantification of serum C-mannosyl tryptophan by novel assay to evaluate renal function and vascular complications in patients with type 2 diabetes.
2021Scientific reports
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
Circulating Metabolites Associate With and Improve the Prediction of All-Cause Mortality in Type 2 Diabetes.
2022Diabetes
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
Gut microbiota mediate melatonin signalling in association with type 2 diabetes.
2022Diabetologia
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
Maternal PBDE exposure disrupts gut microbiome and promotes hepatic proinflammatory signaling in humanized PXR-transgenic mouse offspring over time.
2023Toxicological sciences : an official journal of the Society of Toxicology
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
Plasma Tryptophan-Kynurenine Pathway Metabolites and Risk for Progression to End-Stage Kidney Disease in Patients With Type 2 Diabetes.
2023Diabetes care
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
Identification of potential biomarkers for diabetic cardiomyopathy using LC-MS-based metabolomics.
2024Endocrine connections
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
In-depth investigation of the therapeutic effect of Tribulus terrestris L. on type 2 diabetes based on intestinal microbiota and feces metabolomics.
2024Journal of ethnopharmacology
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
A study on the association between gut microbiota, inflammation, and type 2 diabetes.
2024Applied microbiology and biotechnology
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
Altered neopterin and IDO in kynurenine metabolism based on LC-MS/MS metabolomics study: Novel therapeutic checkpoints for type 2 diabetes mellitus.
2024Clinica chimica acta; international journal of clinical chemistry
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
Metabolomic analysis of retinopathy stages and amputation in type 2 diabetes.
2024Clinical nutrition ESPEN
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
Effects of three Huanglian-derived polysaccharides on the gut microbiome and fecal metabolome of high-fat diet/streptozocin-induced type 2 diabetes mice.
2024International journal of biological macromolecules
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
Inflammation and Prediction of Death in Type 2 Diabetes. Evidence of an Intertwined Link With Tryptophan Metabolism.
2025The Journal of clinical endocrinology and metabolism
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
Indole-3-propionic acid promotes hepatic stellate cells inactivation.
2025Journal of translational medicine
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
Disorders of gut microbiota and fecal-serum metabolic patterns are associated with pulmonary tuberculosis and pulmonary tuberculosis comorbid type 2 diabetes mellitus.
2025Microbiology spectrum
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
High-Coverage Metabolomics Reveals Gut Microbiota-Related Metabolic Traits of Type-2 Diabetes in Serum.
2025Journal of proteome research
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
Urinary and Serum Amino Acids May Be Associated with Podocyte, Proximal Tubule, and Renal Endothelial Injury in Early Diabetic Kidney Disease in Type 2 Diabetes Mellitus Patients.
2025Biomedicines
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
Associations of fecal and blood microbiota-related metabolites with gut microbiota and type 2 diabetes in HIV infection.
2025AIDS (London, England)
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.
Integrating 16S rDNA sequencing analysis and targeted tryptophan metabolomics to reveal potential mechanism of mulberry leaf extract in treating type 2 diabetes mellitus mice.
2025Journal of pharmaceutical and biomedical analysis
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
The effect of date seed powder supplementation on anxiety- and depression-like behaviours, sleep quality and tryptophan-kynurenine metabolism in patients with type 2 diabetes: targeting gut-brain axis.
2025The British journal of nutrition
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
Indole-3-propionic acid links gut dysfunction to diabetic retinopathy: a biomarker and novel therapeutic approach.
2026Gut
Direct disease-relevant human paper with strong clinical, biomarker, or mechanistic framing.
Preclinical supporting evidence
32 papersThe metabolites in peripheral blood mononuclear cells showed greater differences between patients with impaired fasting glucose or type 2 diabetes and healthy controls than those in plasma.
2017Diabetes & vascular disease research
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Tryptophan Metabolism in Patients With Chronic Kidney Disease Secondary to Type 2 Diabetes: Relationship to Inflammatory Markers.
2017International journal of tryptophan research : IJTR
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Association of Tryptophan Metabolites with Incident Type 2 Diabetes in the PREDIMED Trial: A Case-Cohort Study.
2018Clinical chemistry
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Berberine alleviates type 2 diabetic symptoms by altering gut microbiota and reducing aromatic amino acids.
2020Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Neopterin and biopterin levels and tryptophan degradation in patients with diabetes.
2020Scientific reports
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Metabolomics profiles associated with diabetic retinopathy in type 2 diabetes patients.
2020PloS one
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Structural basis for GLP-1 receptor activation by LY3502970, an orally active nonpeptide agonist.
2020Proceedings of the National Academy of Sciences of the United States of America
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Host and gut microbial tryptophan metabolism and type 2 diabetes: an integrative analysis of host genetics, diet, gut microbiome and circulating metabolites in cohort studies.
2022Gut
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Untargeted serum metabolomics and tryptophan metabolism profiling in type 2 diabetic patients with diabetic glomerulopathy.
2021Renal failure
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Pharmacometabolomic profiles in type 2 diabetic subjects treated with liraglutide or glimepiride.
2021Cardiovascular diabetology
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Pi-Dan-Jian-Qing Decoction Ameliorates Type 2 Diabetes Mellitus Through Regulating the Gut Microbiota and Serum Metabolism.
2021Frontiers in cellular and infection microbiology
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Dietary tryptophan and the risk of obesity and type 2 diabetes: Total effect and mediation effect of sleep duration.
2022Obesity (Silver Spring, Md.)
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Indolepropionic acid reduces obesity-induced metabolic dysfunction through colonic barrier restoration mediated via tuft cell-derived IL-25.
2022The FEBS journal
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Analysis of subgingival micro-organisms based on multi-omics and Treg/Th17 balance in type 2 diabetes with/without periodontitis.
2022Frontiers in microbiology
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Diet-rich in wheat bran modulates tryptophan metabolism and AhR/IL-22 signalling mediated metabolic health and gut dysbacteriosis: A novel prebiotic-like activity of wheat bran.
2023Food research international (Ottawa, Ont.)
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Bear bile powder ameliorates type 2 diabetes via modulation of metabolic profiles, gut microbiota, and metabolites.
2022Frontiers in pharmacology
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Red Meat Intake, Indole-3-Acetate, and Dorea longicatena Together Affect Insulin Resistance after Gastric Bypass.
2023Nutrients
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Indoleacrylic acid produced by Parabacteroides distasonis alleviates type 2 diabetes via activation of AhR to repair intestinal barrier.
2023BMC biology
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Metabolic Profile of Individuals with and without Type 2 Diabetes from Sub-Saharan Africa.
2023Journal of proteome research
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Integrated 16S rRNA sequencing and nontargeted metabolomics analysis to reveal the mechanisms of Yu-Ye Tang on type 2 diabetes mellitus rats.
2023Frontiers in endocrinology
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Effect modification of tumor necrosis factor-α on the kynurenine and serotonin pathways in major depressive disorder on type 2 diabetes mellitus.
2024European archives of psychiatry and clinical neuroscience
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Sex Differences in Branched-chain Amino Acid and Tryptophan Metabolism and Pathogenesis of Youth-onset Type 2 Diabetes.
2024The Journal of clinical endocrinology and metabolism
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Inulin Reduces Kidney Damage in Type 2 Diabetic Mice by Decreasing Inflammation and Serum Metabolomics.
2024Journal of diabetes research
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Interplay between gut microbiota and tryptophan metabolism in type 2 diabetic mice treated with metformin.
2024Microbiology spectrum
Disease-relevant preclinical or model-based paper useful as supporting evidence.
The microbiota-dependent tryptophan metabolite alleviates high-fat diet-induced insulin resistance through the hepatic AhR/TSC2/mTORC1 axis.
2024Proceedings of the National Academy of Sciences of the United States of America
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Effect of dapagliflozin on the serum metabolome in patients with type 2 diabetes mellitus.
2025Journal of diabetes and metabolic disorders
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Theabrownin Alleviates Type 2 Diabetes Mellitus in db/db Mice via Modulating LPS/GLP-1 Levels and Restoring Islet Cells: Evidence from Gut-Pancreas Axis.
2025Journal of agricultural and food chemistry
Disease-relevant preclinical or model-based paper useful as supporting evidence.
A microbial amino-acid-conjugated bile acid, tryptophan-cholic acid, improves glucose homeostasis via the orphan receptor MRGPRE.
2025Cell
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Metabolite perturbations in type 1 diabetes associated with metabolic dysfunction-associated steatotic liver disease.
2025Frontiers in endocrinology
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Diabetes-associated modifications in gut microbiota and tryptophan metabolism: implications for macrophage polarization and wound repair in mice.
2026BMC microbiology
Disease-relevant preclinical or model-based paper useful as supporting evidence.
The microbial tryptophan metabolite indole acts on the gastrointestinal tract to improve glucose homeostasis in a mouse model of diabetes by enhancing GLP-1 secretion and L cell differentiation.
2026Diabetologia
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Extracellular Polysaccharides of Eurotium cristatum from Fu Brick Tea Ameliorated Type 2 Diabetes in Mice by Remodeling of Gut Microbiota-Dependent Tryptophan Metabolism to Activate the Hepatic AhR/TSC2/mTORC1 Axis.
2026Journal of agricultural and food chemistry
Disease-relevant preclinical or model-based paper useful as supporting evidence.
Review supporting evidence
18 papersSLC30A8 mutations in type 2 diabetes.
2015Diabetologia
Relevant review or meta-analysis for the signal-disease area.
Food, immunity, and the microbiome.
2015Gastroenterology
Relevant review or meta-analysis for the signal-disease area.
The pathogenesis and pathophysiology of gestational diabetes mellitus: Deductions from a three-part longitudinal metabolomics study in China.
2017Clinica chimica acta; international journal of clinical chemistry
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.
Diabesity and mood disorders: Multiple links through the microbiota-gut-brain axis.
2019Molecular aspects of medicine
Relevant review or meta-analysis for the signal-disease area.
Therapeutic mechanisms of traditional Chinese medicine to improve metabolic diseases via the gut microbiota.
2021Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie
Relevant review or meta-analysis for the signal-disease area.
Control of Mesenchymal Stromal Cell Senescence by Tryptophan Metabolites.
2021International journal of molecular sciences
Relevant review or meta-analysis for the signal-disease area.
Tryptophan Metabolism in Atherosclerosis and Diabetes.
2022Current medicinal chemistry
Relevant review or meta-analysis for the signal-disease area.
Characteristics of the Gut Microbiota and Potential Effects of Probiotic Supplements in Individuals with Type 2 Diabetes mellitus.
2021Foods (Basel, Switzerland)
Relevant review or meta-analysis for the signal-disease area.
Emerging effects of tryptophan pathway metabolites and intestinal microbiota on metabolism and intestinal function.
2022Amino acids
Relevant review or meta-analysis for the signal-disease area.
Indolepropionic Acid, a Gut Bacteria-Produced Tryptophan Metabolite and the Risk of Type 2 Diabetes and Non-Alcoholic Fatty Liver Disease.
2022Nutrients
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.
Targeting the gut microbiota and its metabolites for type 2 diabetes mellitus.
2023Frontiers in endocrinology
Relevant review or meta-analysis for the signal-disease area.
Abnormal tryptophan catabolism in diabetes mellitus and its complications: Opportunities and challenges.
2023Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie
Relevant review or meta-analysis for the signal-disease area.
Kynurenine pathway in type 2 diabetes: Role of metformin.
2024Drug development research
Relevant review or meta-analysis for the signal-disease area.
Recent advances in precision nutrition and cardiometabolic diseases.
2025Revista espanola de cardiologia (English ed.)
Relevant review or meta-analysis for the signal-disease area.
Tryptophan Indole Derivatives: Key Players in Type 2 Diabetes Mellitus.
2025Diabetes, metabolic syndrome and obesity : targets and therapy
Relevant review or meta-analysis for the signal-disease area.
Bidirectional relationship between statins and the gut microbiota: implications for cardiovascular health, diabetes, and cancer.
2025Xenobiotica; the fate of foreign compounds in biological systems
Relevant review or meta-analysis for the signal-disease area.