Tryptophan metabolism in inter-organ communication and its potential applications for disease prevention and control

Tryptophan (Trp) is an indispensable amino acid which, in addition to being incorporated into proteins, is involved in energy metabolism and gives rise to metabolites with pivotal functions in modulating a variety of physiological processes in mammals. These metabolites are generated in the body through two major metabolic pathways, namely the kynurenine and the 5-hydroxytryptamine pathways. Within the intestinal microbiota, Trp is a precursor for the synthesis of indole and indole-related compounds that have been shown to be active on several host’s tissues and organs. Increasing experimental and clinical studies demonstrated the versatile functions of Trp metabolites in various aspects of physiological and pathophysiological processes involved in energy and nutrient metabolism, as well as organ development and inter-organ communication through both peripheral and local regulatory networks. Recent research highlights the importance of such inter-organ communication in the maintenance of the host health. In this context, this review comprehensively summarizes the function of Trp metabolites and their physiological implications in communication between different organs and tissues, and between the intestinal microbiota and the lodging host’s cells. The metabolic connection between the intestine and other organs such as brain, liver, lung, kidney, and muscle are presented. The potential therapeutic applications of the regulation of Trp metabolism in different pathophysiological situations are discussed.

• Publication year

  2025

• Venue

  The Innovation Life

• Publication date

  Unknown publication date

• Fields of study

  Not labeled

• Identifiers
  DOI 10.59717/j.xinn-life.2026.100177
• External record

  Open on Semantic Scholar

• Source metadata

  Semantic Scholar

• No claims are published for this paper.

• No concepts are published for this paper.

• 3,3′-Diindolylmethane improves pathology and neurological outcome following traumatic brain injury

  2025cited by this paper
• Time-restricted feeding promotes glucagon-like peptide-1 secretion and regulates appetite via tryptophan metabolism of gut Lactobacillus in pigs

  2025cited by this paper
• Mitochondrial dysfunction and lipid alterations in primary sclerosing cholangitis

  2025cited by this paper
• Benefits of equilibrium between microbiota- and host-derived ligands of the aryl hydrocarbon receptor after stroke in aged male mice

  2025cited by this paper
• Identification and validation of aryl hydrocarbon receptor-associated hub genes in ulcerative colitis via integrated bioinformatics analysis

  2025cited by this paper
• Bifidobacterium adolescentis-derived nicotinic acid improves host skeletal muscle mitochondrial function to ameliorate sarcopenia.

  2025cited by this paper
• Harnessing IDO inhibitors to optimize cancer immunotherapy

  2025cited by this paper
• Interkingdom signaling between gastrointestinal hormones and the gut microbiome

  2025cited by this paper
• Elevated initial blood kynurenine is associated with increased odds of post-stroke infection Kynurenine and post-stroke infection

  2025cited by this paper
• Acute decrease in the plasma tryptophan-to-large-neutral-amino-acids ratio attenuates the effects of L-tryptophan on gut hormones and energy intake in healthy males: a randomized, cross-over, exploratory trial.

  2025cited by this paper
• Targeting Lactobacillus johnsonii to reverse chronic kidney disease

  2024cited by this paper
• Systematic optimization of prime editing for the efficient functional correction of CFTR F508del in human airway epithelial cells

  2024cited by this paper
• The Multifaceted Role of L-Type Amino Acid Transporter 1 at the Blood–Brain Barrier: Structural Implications and Therapeutic Potential

  2024cited by this paper
• Indole-3-Carboxaldehyde Alleviates LPS-Induced Intestinal Inflammation by Inhibiting ROS Production and NLRP3 Inflammasome Activation

  2024cited by this paper
• Blautia Coccoides is a Newly Identified Bacterium Increased by Leucine Deprivation and has a Novel Function in Improving Metabolic Disorders

  2024cited by this paper
• Ca2+/calmodulin-dependent protein kinase II β decodes ER Ca2+ transients to trigger autophagosome formation.

  2024cited by this paper
• The therapeutic potential of dietary intervention: based on the mechanism of a tryptophan derivative-indole propionic acid on metabolic disorders

  2024cited by this paper
• Microbial colonization programs are structured by breastfeeding and guide healthy respiratory development.

  2024cited by this paper
• PMN-MDSC: A Culprit Behind Immunosenescence and Increased Susceptibility to Clostridioides difficile Infection During Aging

  2024cited by this paper
• The emerging role of gut hormones

  2024cited by this paper
• The impact of 5-hydroxytryptophan supplementation on sleep quality and gut microbiota composition in older adults: A randomized controlled trial.

  2024cited by this paper
• Indole-3-acetic acid attenuates pulmonary fibrosis by modulating lung microbiota, inhibiting fibroblast activation, and alleviating alveolar epithelial cell senescence.

  2024cited by this paper
• Psilocybin restrains activity-based anorexia in female rats by enhancing cognitive flexibility: contributions from 5-HT1A and 5-HT2A receptor mechanisms

  2024cited by this paper
• Hydrogen-rich water alleviates asthma airway inflammation by modulating tryptophan metabolism and activating aryl hydrocarbon receptor via gut microbiota regulation.

  2024cited by this paper
• From gut microbiota to brain: implications on binge eating disorders

  2024cited by this paper
• Human gut-associated Bifidobacterium species salvage exogenous indole, a uremic toxin precursor, to synthesize indole-3-lactic acid via tryptophan

  2024cited by this paper
• Kynurenine acts as a signaling molecule to attenuate pulmonary fibrosis by enhancing the AHR-PTEN axis

  2024cited by this paper
• Changes in kynurenine metabolites in the gray and white matter of the dorsolateral prefrontal cortex of individuals affected by schizophrenia

  2024cited by this paper
• Genome‐Wide Profiling of H3K27ac Identifies TDO2 as a Pivotal Therapeutic Target in Metabolic Associated Steatohepatitis Liver Disease

  2024cited by this paper
• Microbiota-derived indoles alleviate intestinal inflammation and modulate microbiome by microbial cross-feeding

  2024cited by this paper
• Bifidobacterium animalis Probio-M8 improves sarcopenia physical performance by mitigating creatine restrictions imposed by microbial metabolites

  2024cited by this paper
• Eugenol promotes appetite through TRP channels mediated‐CaMKK2/AMPK signaling pathway

  2023cited by this paper
• The Melatonin–Mitochondrial Axis: Engaging the Repercussions of Ultraviolet Radiation Photoaging on the Skin’s Circadian Rhythm

  2023cited by this paper
• Atlas of gut microbe-derived products from aromatic amino acids and risk of cardiovascular morbidity and mortality.

  2023cited by this paper
• Dietary tryptophan metabolite released by intratumoral Lactobacillus reuteri facilitates immune checkpoint inhibitor treatment.

  2023cited by this paper
• The gut microbiota contributes to the pathogenesis of anorexia nervosa in humans and mice

  2023cited by this paper
• Untargeted and targeted metabolomics reveal bile acid profile changes in rats with ethylene glycol-induced calcium oxalate nephrolithiasis.

  2023cited by this paper
• Microbiome and tryptophan metabolomics analysis in adolescent depression: roles of the gut microbiota in the regulation of tryptophan-derived neurotransmitters and behaviors in human and mice

  2023cited by this paper
• Theabrownin inhibits obesity and non-alcoholic fatty liver disease in mice via serotonin-related signaling pathways and gut-liver axis

  2023cited by this paper
• Hydroxytryptophan biosynthesis by a family of heme-dependent enzymes in bacteria

  2023cited by this paper
• Absolute quantification of the microbiota spatial distribution in the murine large intestine

  2023cited by this paper
• Mechanism-based inhibition of gut microbial tryptophanases reduces serum indoxyl sulfate.

  2023cited by this paper
• Evaluation of pro-regenerative and anti-inflammatory effects of isolecanoric acid in the muscle: Potential treatment of Duchenne Muscular Dystrophy.

  2023cited by this paper
• Metabolic Communication by SGLT2 Inhibition

  2023cited by this paper
• Phase I/II trial of BMS-986,205 and nivolumab as first line therapy in hepatocellular carcinoma

  2023cited by this paper
• Microbiota-derived 3-IAA influences chemotherapy efficacy in pancreatic cancer

  2023cited by this paper
• Rosa laevigata Michx. Polysaccharide Ameliorates Diabetic Nephropathy in Mice through Inhibiting Ferroptosis and PI3K/AKT Pathway-Mediated Apoptosis and Modulating Tryptophan Metabolism

  2023cited by this paper
• Supplementation with the Probiotic Strains Bifidobacterium longum and Lactiplantibacillus rhamnosus Alleviates Glucose Intolerance by Restoring the IL-22 Response and Pancreatic Beta Cell Dysfunction in Type 2 Diabetic Mice

  2023cited by this paper
• Sex- and suicide-specific alterations in the kynurenine pathway in the anterior cingulate cortex in major depression

  2023cited by this paper
• Plasma indole-3-aldehyde as a novel biomarker of acute kidney injury after cardiac surgery: a reanalysis using prospective metabolomic data

  2023cited by this paper
• Abnormal tryptophan catabolism in diabetes mellitus and its complications: Opportunities and challenges.

  2023cited by this paper
• The Role of Tryptophan Metabolism in the Occurrence and Progression of Acute and Chronic Kidney Diseases.

  2023cited by this paper
• The role of Neurochemicals, Stress Hormones and Immune System in the Positive Feedback Loops between Diabetes, Obesity and Depression

  2023cited by this paper
• Tryptophan Metabolism and Gut Microbiota: A Novel Regulatory Axis Integrating the Microbiome, Immunity, and Cancer

  2023cited by this paper
• Influence of Different Light Spectra on Melatonin Synthesis by the Pineal Gland and Influence on the Immune System in Chickens

  2023cited by this paper
• Melatonin supplementation promotes muscle fiber hypertrophy and regulates lipid metabolism of skeletal muscle in weaned piglets.

  2023cited by this paper
• Tryptophan metabolism in health and disease.

  2023cited by this paper
• The serotonin transporter sustains human brown adipose tissue thermogenesis

  2023cited by this paper
• A multisociety Delphi consensus statement on new fatty liver disease nomenclature

  2023cited by this paper
• Horizontal transmission of gut microbiota attenuates mortality in lung fibrosis

  2023cited by this paper
• Plasma Tryptophan-Kynurenine Pathway Metabolites and Risk for Progression to End-Stage Kidney Disease in Patients With Type 2 Diabetes

  2023cited by this paper
• Type-2-low severe asthma endotypes for new treatments: the new asthma frontier.

  2023cited by this paper
• Dynamics of the gut-liver axis in rats with varying fibrosis severity

  2022cited by this paper
• Clinical, gut microbial and neural effects of a probiotic add-on therapy in depressed patients: a randomized controlled trial

  2022cited by this paper
• Microbial-derived metabolites as a risk factor of age-related cognitive decline and dementia

  2022cited by this paper
• Edible Mushrooms as a Potential Component of Dietary Interventions for Major Depressive Disorder

  2022cited by this paper
• Diet and the gut-lung axis in cystic fibrosis – direct & indirect links

  2022cited by this paper
• The effect of probiotic and synbiotic supplementation on appetite-regulating hormones and desire to eat: A systematic review and meta-analysis of clinical trials.

  2022cited by this paper
• Obesity medication lorcaserin activates brainstem GLP-1 neurons to reduce food intake and augments GLP-1 receptor agonist induced appetite suppression

  2022cited by this paper
• Indole-3-propionic acid alleviates ischemic brain injury in a mouse middle cerebral artery occlusion model.

  2022cited by this paper
• The gut microbiota-brain axis: Role of the gut microbial metabolites of dietary food in obesity.

  2022cited by this paper
• Bifidobacterium longum mediated tryptophan metabolism to improve atopic dermatitis via the gut-skin axis

  2022cited by this paper
• Host/microbiota interactions-derived tryptophan metabolites modulate oxidative stress and inflammation via aryl hydrocarbon receptor signaling.

  2022cited by this paper
• Effects of pharmacological treatment on metabolomic alterations in animal models of depression

  2022cited by this paper
• The Regulatory Role of the Central and Peripheral Serotonin Network on Feeding Signals in Metabolic Diseases

  2022cited by this paper
• Tryptophan-rich diet ameliorates chronic unpredictable mild stress induced depression- and anxiety-like behavior in mice: The potential involvement of gut-brain axis.

  2022cited by this paper
• A metabolically engineered bacterium controls autoimmunity and inflammation by remodeling the pro-inflammatory microenvironment

  2022cited by this paper
• Indole intercepts the communication between enteropathogenic E. coli and Vibrio cholerae

  2022cited by this paper
• Tryptophan metabolites in depression: Modulation by gut microbiota

  2022cited by this paper
• A Potential Fatty Acid Metabolism-Related Gene Signature for Prognosis in Clear Cell Renal Cell Carcinoma

  2022cited by this paper
• Maturation and specialization of group 2 innate lymphoid cells through the lung-gut axis

  2022cited by this paper
• A critical analysis of eating disorders and the gut microbiome

  2022cited by this paper
• Tryptophan Metabolism in Depression: A Narrative Review with a Focus on Serotonin and Kynurenine Pathways

  2022cited by this paper
• Multi-omics analyses of airway host–microbe interactions in chronic obstructive pulmonary disease identify potential therapeutic interventions

  2022cited by this paper
• Gut Bifidobacteria enrichment following oral Lactobacillus-supplementation is associated with clinical improvements in children with cystic fibrosis

  2022cited by this paper
• Assessment toxic effects of exposure to 3-indoleacetic acid via hemato-biochemical, hormonal, and histopathological screening in rats

  2022cited by this paper
• The intestinal microbial metabolite nicotinamide n-oxide prevents herpes simplex encephalitis via activating mitophagy in microglia

  2022cited by this paper
• The serotonin theory of depression: a systematic umbrella review of the evidence

  2022cited by this paper
• Acts of appetite: neural circuits governing the appetitive, consummatory, and terminating phases of feeding

  2022cited by this paper
• Synbiotics of Bifidobacterium breve MCC1274 and lactulose enhances production of tryptophan metabolites in fermented human fecal communities.

  2022cited by this paper
• Association between the indole pathway of tryptophan metabolism and subclinical depressive symptoms in obesity: a preliminary study

  2022cited by this paper
• Gut Microbially Produced Indole-3-Propionic Acid Inhibits Atherosclerosis by Promoting Reverse Cholesterol Transport and Its Deficiency Is Causally Related to Atherosclerotic Cardiovascular Disease

  2022cited by this paper
• The fibrogenic niche in kidney fibrosis: components and mechanisms

  2022cited by this paper
• Urinary Microbial and Metabolomic Profiles in Kidney Stone Disease

  2022cited by this paper
• Deciphering an AgRP-serotoninergic neural circuit in distinct control of energy metabolism from feeding

  2021cited by this paper
• The kynurenine pathway in major depression: What we know and where to next.

  2021cited by this paper
• Exogenous melatonin decreases circadian misalignment and body weight among early types

  2021cited by this paper
• Fate of undigested proteins in the pig large intestine: What impact on the colon epithelium?

  2021cited by this paper
• A Systems Biology Approach to Investigating the Interaction between Serotonin Synthesis by Tryptophan Hydroxylase and the Metabolic Homeostasis

  2021cited by this paper
• Serum 5-Hydroxyindoleacetic Acid and Ratio of 5-Hydroxyindoleacetic Acid to Serotonin as Metabolomics Indicators for Acute Oxidative Stress and Inflammation in Vancomycin-Associated Acute Kidney Injury

  2021cited by this paper

• No citing papers are available for this paper.