ReviewBiomedicines2021
Immune Influencers in Action: Metabolites and Enzymes of the Tryptophan-Kynurenine Metabolic Pathway.
Review in Biomedicines, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 161 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
161 citing papers in PubMed, 1 synthesis or guideline pooled it.
- Pooled it
- Multiple Pre-Treatment miRNAs Levels in Untreated Major Depressive Disorder Patients Predict Early Response to Antidepressants and Interact with Key Pathways.International journal of molecular sciences · 2022Trial
- The Tryptophan-Kynurenine Pathway as a Key Mediator of the Gut-Brain Axis in Depression and Alzheimer's Disease.International journal of molecular sciences · 2026Review
- Virobiome-mediated regulation of microbiota-gut-brain axis signaling and neuroimmune homeostasis.Cell communication and signaling : CCS · 2026Review
- Metabolic Signatures Associated with COVID-19 Vaccination in Serum from Healthy Individuals.Vaccines · 2026Article
- Mechanism-First Psychobiotics: Fermented Vegetables, Dairy, and Soy for Depression and Anxiety.International journal of molecular sciences · 2026Review
- Altered Kynurenine Pathway Metabolism in Drug-naive Children and Adolescents with Generalized Anxiety Disorder.Clinical psychopharmacology and neuroscience : the official scientific journal of the Korean College of Neuropsychopharmacology · 2026Article
- Gut-heart immuno-metabolic disruption associated with inflammaging and subclinical coronary artery disease in people with HIV on antiretroviral therapy.Immunity & ageing : I & A · 2026Article
- Kynurenine Pathway, Nrf2 and NF-κB Cross-Regulation in the CNS: An Overview.Molecular neurobiology · 2026Review
- Nonlinear threshold and association of depressive symptoms with pain in middle-aged and older Chinese adults: a cross-sectional and cohort study.Scientific reports · 2026Article
- Central and Peripheral Characterization of Key Kynurenine Pathway Metabolites in Mexican Patients with Multiple Sclerosis: An Exploratory Study.Pharmaceuticals (Basel, Switzerland) · 2026Article
- Molecular mechanisms and therapeutic potential of tryptophan metabolism in gut-brain signaling transduction: a narrative review.Journal of neuroinflammation · 2026Review
- From Signal to Symptom: EEG Paroxysms and Background Slowing as Potential Biomarkers and Compensatory Failures in Treatment-Resistant Schizophrenia.Biomedicines · 2026Article
- Dietary advanced glycation products combined with chronic restraint stress induced anxiety-like and depression-like behaviors in male mice.NPJ science of food · 2026Article
- Tryptophan metabolism alterations in neurological and psychiatric diseases: Molecular mechanisms and pharmacological targets.Metabolic brain disease · 2026Review
- Metformin and Sitagliptin Impact the Brain Kynurenine Pathway: Region-Specific Modulation of Neuroactive Metabolites in Non-Diabetic Male Rats.Molecules (Basel, Switzerland) · 2026Article
- Receptor-Mitochondria Crosstalk in the Kynurenine Metabolic Pathway: Integrating Metabolomics and Clinical Mass Spectrometry.Antioxidants (Basel, Switzerland) · 2026Review
- Rumen microbiota modulates metabolic stress in high-yield dairy cows: insights from early to peak lactation.Microbiome · 2026Article
- Research progress on the microbiota-gut-brain axis in autism spectrum disorder: a narrative review.Frontiers in microbiology · 2026Review
- The kynurenine pathway in depression and schizophrenia: convergent signals, divergent states, and clinical signatures.EXCLI journal · 2026Review
101 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
6 authors.
Funding
Abstract
The tryptophan (TRP)-kynurenine (KYN) metabolic pathway is a main player of TRP metabolism through which more than 95% of TRP is catabolized. The pathway is activated by acute and chronic immune responses leading to a wide range of illnesses including cancer, immune diseases, neurodegenerative diseases and psychiatric disorders. The presence of positive feedback loops facilitates amplifying the immune responses vice versa. The TRP-KYN pathway synthesizes multifarious metabolites including oxidants, antioxidants, neurotoxins, neuroprotectants and immunomodulators. The immunomodulators are known to facilitate the immune system towards a tolerogenic state, resulting in chronic low-grade inflammation (LGI) that is commonly present in obesity, poor nutrition, exposer to chemicals or allergens, prodromal stage of various illnesses and chronic diseases. KYN, kynurenic acid, xanthurenic acid and cinnabarinic acid are aryl hydrocarbon receptor ligands that serve as immunomodulators. Furthermore, TRP-KYN pathway enzymes are known to be activated by the stress hormone cortisol and inflammatory cytokines, and genotypic variants were observed to contribute to inflammation and thus various diseases. The tryptophan 2,3-dioxygenase, the indoleamine 2,3-dioxygenases and the kynurenine-3-monooxygenase are main enzymes in the pathway. This review article discusses the TRP-KYN pathway with special emphasis on its interaction with the immune system and the tolerogenic shift towards chronic LGI and overviews the major symptoms, pro- and anti-inflammatory cytokines and toxic and protective KYNs to explore the linkage between chronic LGI, KYNs, and major psychiatric disorders, including depressive disorder, bipolar disorder, substance use disorder, post-traumatic stress disorder, schizophrenia and autism spectrum disorder.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.