α-SYN	α-synuclein
BBB	Blood–brain barrier
BDNF	Brain-derived neurotrophic factor
CAT	Catalase
CNS	Central nervous system
DA	Dopamine
DAB	3,3′-diaminobenzidine
DOPAC	3,4-dihydroxyphenylacetic acid
ELISA	Enzyme-linked immunosorbent assay
ENS	Enteric nervous system
GAPDH	Glyceraldehyde-3-phosphate dehydrogenase
GDNF	Glial cell line-derived neurotrophic factor
GFAP	Glial fibrillary acidic protein
GSH	Glutathione
HPLC	High Performance Liquid Chromatography
HVA	Homovanillic acid
Iba1	Ionized calcium binding adapter molecule 1
IL-1β	Interleukin-1β
IL-6	Interleukin-6
IL-10	Interleukin-10
IHC	Immunohistochemistry
LDA	Linear discriminant analysis
L-DOPA	Levodopa
LPS	Lipopolysaccharide
MGBA	Microbiota–gut–brain axis
MPTP	1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine
MRS	De Man Rogosa Sharpe
NBT	Narrow-beam test
OUT	Operational taxonomic unit
OFT	Open field test
PCA	Principal component analysis
PCoA	Principal coordinate analysis
PD	Parkinson’s disease
perMANOVA	Permutational multivariate analysis of variance
PICRUSt	Phylogenetic Investigation of Communities by Reconstruction of Unobserved States
PT	Pole test
QIIME	Quantitative Insights into Microbial Ecology
qRT-PCR	Quantitative real-time polymerase chain reaction assay
ROS	Reactive oxygen species
RTR	Rotarod test
SCFAs	Short-chain fatty acids
SEM	Standard error of mean
SN	Substantia nigra
SOD	Superoxide dismutase
TNF-α	Tumor necrosis factor-α
TH	Tyrosine hydroxylase
TrkB	Tyrosine Kinase receptor B
ZO-1	Zonula occludens-1
5-HT	5-hydroxytryptamine
5-HIAA	5-hydroxyindoleacetic acid