3HAAO	3-hydroxyanthranilate 3,4-dioxygenase
3-HANA	3-hydroxyanthranilic acid
3-HAO	3-hydroxyanthranilic acid 3,4-dioxygenase
3-HK	3-hydroxykynurenine
6-OHDA	6-hydroxydopamine
AA	anthranilic acid
ACMS	α-amino-α-carboxymuconate-ε-semialdehyde
ACMSD	α-amino-β-carboxymuconate-ε-semialdehyde decarboxylase
AhR	aryl hydrocarbon receptor
AIP	protein kinase c-Scr AhR-interacting protein
ArAT	aromatic amino acid aminotransferase
BBB	Blood–brain barrier
CNS	central nervous system
CSF	cerebrospinal fluid
CYP	cytochrome P450
FMT	fecal microbiota transplantation
GPR35	G-protein-coupled orphan receptor 35
HSP90	heat shock protein 90
I3S	indoxyl-3-sulfate
IAA	indole-3-acetic acid
IAAld	indole-3-acetaldehyde
IDO	indoleamine 2,3-dioxygenase
IE	indole ethanol
IL	interleukin
ILA	indole-3-lactic acid
ILDH	indole lactic acid dehydrogenase
IPA	indole-3-propionic acid
IS	indoxyl-3-sulfate
ITE	2-(19H-indole-39-carbonyl)-thiazole-4-carboxylic acid methyl ester
KAT I–IV	kynurenine aminotransferase I–IV
KMO	kynurenine 3-monooxygenase
KYN	kynurenine
KYNA	kynurenic acid
KYNU	kynureninase
L-DOPA	levodopa
LNAA	large neutral amino acid
LNAAT	large neutral amino acid transporter
LPHC	low-protein, high-carbohydrate
LPS	lipopolysaccharide
MHC	major histocompatibility complex
MIND	diet Mediterranean-DASH Intervention for Neurodegenerative Delay
MPP+	1-methyl-4-phenylpyridinium ion
MPTP	1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine
NAD+	nicotinamide adenine dinucleotide
NF-κB	nuclear factor kappa-light-chain enhancer of activated B cells
NMDA	N-methyl-D-aspartate
PD	Parkinson’s disease
PUFAs	polyunsaturated fatty acids
PXR	pregnane X receptor
QUIN	quinolinic acid
ROS	reactive oxygen species
SCFA	short-chain fatty acid
SN	substantia nigra
Src	Src family kinases
TCDD	2,3,7,8-tetrachlorodibenzo-p-dioxin
TDO	tryptophan 2,3-dioxygenase;
TLR-4	Toll-like receptor
Trp	tryptophan
UbcH7	ubiquitin-conjugating enzyme H7
XA	xanthurenic acid
XRE, DRE	xenobiotic responsive element