5-HT	5-hydroxytryptamine (serotonin)
ADE	adenine-induced chronic kidney disease
APOE ε4	apolipoprotein E ε4
ASK1	apoptosis signal-regulating kinase 1
BDNF	brain-derived neurotrophic factor
CAT	catalase
CCK	cholecystokinin
CFU	colony-forming unit
CSF	cerebrospinal fluid
CXCR6	C-X-C chemokine receptor type 6
DA	dopamine
DAO	diamine oxidase
DSS	dextran sodium sulfate
EECs	enteroendocrine cells
FXR	farnesoid X receptor
GABA	gamma-aminobutyric acid
Galp	Galactopyranose
GDNF	glial cell line-derived neurotrophic factor
Glcp	Glucopyranose
GLP-1	glucagon-like peptide-1
GM-CSF	granulocyte-macrophage colony-stimulating factor
GPNE-I	ginseng polysaccharide NE-I
GPR41/43	G protein-coupled receptor 41/43
GSH	glutathione
GSH-Px	glutathione peroxidase
HDAC6	histone deacetylase 6
HPA axis	hypothalamic-pituitary-adrenal axis
IFNγ	interferon-gamma
IgA	immunoglobulin A
IL-1β, IL-6, IL-10	interleukin-1β, -6, -10
IL-2, IL-17	interleukin-2, -17
ISAPP	International Scientific Association for Probiotics and Prebiotics
JNK	c-Jun N-terminal kinase
Keap1	Kelch-like ECH-associated protein 1
LPS	lipopolysaccharide
Lrp5	low-density lipoprotein receptor-related protein 5
MDA	malondialdehyde
MGBA	microbiota-gut-brain axis
MIBG	meta-iodobenzylguanidine
MPTP	1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine
MRI	magnetic resonance imaging
NE	norepinephrine
NF-κB	nuclear factor kappa B
NK cells	natural killer cells
NLRP3	NLR family pyrin domain containing 3
NMDA	N-methyl-D-aspartate
Nrf2	nuclear factor erythroid 2–related factor 2
NTS	nucleus tractus solitarius
p38 MAPK	p38 mitogen-activated protein kinase
PD	Parkinson’s disease
PET	positron emission tomography
PIGD	postural instability/gait difficulty
PYY	Peptide YY
RBD	rapid eye movement sleep behavior disorder
ROS	reactive oxygen species
SCFAs	short-chain fatty acids
SIgA	secretory immunoglobulin A
SLAMF6	signaling lymphocytic activation molecule family member 6
SOD	superoxide dismutase
STAT1/6	signal transducer and activator of transcription 1/6
TD	tremor-dominant
TGF-β	transforming growth factor-beta
Th17	T helper 17 cells
TLR4	Toll-like receptor 4
TNF-α	tumor necrosis factor-alpha
TRAIL-DR5	TNF-related apoptosis-inducing ligand—Death receptor 5
Tregs	regulatory T cells
TXN	thioredoxin
UPDRS	Unified Parkinson’s Disease Rating Scale
VH/CD	villus height/crypt depth
ZO-1	zonula occludens-1
α-syn	alpha-synuclein