AA	anthranilic acid
AAD	amino acid decarboxylase
AD	Alzheimer’s disease
AhR	aryl hydrocarbon receptor
AMPA	alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid
ALS	amyotrophic lateral sclerosis
ArAT	aromatic amino acid aminotransferase
BBB	blood–brain barrier
BPF	Bisphenol F
CA	cinnabarinic acid
CKD	chronic kidney disease
CNS	central nervous system
CrPic	chromium picolinate
GPR35	G-protein-coupled receptor 35
3-HAA	3-hydroxyanthranilic acid
HD	Huntington’s disease
3-HK	3-hydroxykynurenine
IAA	indole-3-acetic acid
IaaH	indole-3-acetamide hydrolase
IAAld	indole-3-acetaldehyde
IAcA	3-indole acrylic acid
IAld	indole-3-aldehyde
IAM	indole-3-acetamide
IDO	indoleamine 2,3-dioxygenase
ILA	indole-3-lactic acid
INS	indoxyl sulfate
IPA	indole-3-propionic acid
IPyA	indole-3-pyruvic acid
JAK/STAT	Janus kinase/signal transducers and activators of transcription
KATs	kynurenine aminotransferases
KYN	kynurenine
KYNA	kynurenic acid
LPS	lipopolysaccharide
MAPK	mitogen-activated protein kinase
mGluRs	metabotropic glutamate receptors
MS	multiple sclerosis
NAD	nicotinamide adenine dinucleotide
NMDA	N-methyl-D-aspartate
PA	picolinic acid
PD	Parkinson’s disease
QUIN	quinolinic acid
ROS	reactive oxygen species
TDO	tryptophan 2,3-dioxygenase
TEAC	Trolox equivalent antioxidant capacity
TMO	tryptophan-2-monooxygenase
TNA	tryptophanase
TrD	tryptophan decarboxylase
Tregs	regulatory T cells
Trp	tryptophan
XA	xanthurenic acid