Cited by 519Tryptophan and brain disordersGut microbiota and healthAmino Acid Enzymes and Metabolism

Tryptophan metabolism and gut-brain homeostasis

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Roth, William, Zadeh, Kimia, Vekariya, Rushi, Ge, Yong, Mohamadzadeh, Mansour·2021·International Journal of Molecular Sciences

Abstract

Tryptophan is an essential amino acid critical for protein synthesis in humans that has emerged as a key player in the microbiota-gut-brain axis. It is the only precursor for the neurotransmitter serotonin, which is vital for the processing of emotional regulation, hunger, sleep, and pain, as well as colonic motility and secretory activity in the gut. Tryptophan catabolites from the kynurenine degradation pathway also modulate neural activity and are active in the systemic inflammatory cascade. Additionally, tryptophan and its metabolites support the development of the central and enteric nervous systems. Accordingly, dysregulation of tryptophan metabolites plays a central role in the pathogenesis of many neurologic and psychiatric disorders. Gut microbes influence tryptophan metabolism directly and indirectly, with corresponding changes in behavior and cognition. The gut microbiome has thus garnered much attention as a therapeutic target for both neurologic and psychiatric disorders where tryptophan and its metabolites play a prominent role. In this review, we will touch upon some of these features and their involvement in health and disease.

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Authors
Roth, W., Zadeh, K., Vekariya, R., Ge, Y., & Mohamadzadeh, M.
Affiliations
University of Florida (US)
Corresponding author
  • Roth, William
  • Mohamadzadeh, Mansour
Venue
International Journal of Molecular Sciences
Publisher
MDPI AG
Published
2021-03-15
Volume
22
Issue
6
Pages
2973
ISSN
1422-0067 (ISSN-L)
OpenAlex
W3137164735
Cited by
519
References
194
Citations by year
2026: 102 · 2025: 150 · 2024: 139 · 2023: 72 · 2022: 46 · 2021: 10
FWCI
6.30
Type
journal article
Language
en
Open access
Locations
  • International Journal of Molecular Sciences (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
Funders
National Institutes of Health (DK109560C, R01AI154630-01)
Topics
  • Life Sciences › Neuroscience › Biological Psychiatry › Tryptophan and brain disorders
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Gut microbiota and health
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Biochemistry › Amino Acid Enzymes and Metabolism
Keywords
tryptophan metabolism, gut-brain axis, gut microbiota, serotonin, kynurenine pathway, tryptophan catabolites, neuroinflammation, enteric nervous system, neurological disorders, mental illness, microbiota-targeted therapy
MeSH terms
Gastrointestinal Microbiome, Brain, Colon, Homeostasis, Humans, Hunger, Kynurenine, Pain, Serotonin, Sleep, Tryptophan, Enteric Nervous System

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