AD	Alzheimer’s disease
CI	confidence interval
CNS	central nervous system
GABA	γ-aminobutyric acid
GWAS	genome-wide association study
1KGP	International 1000 Genomes Project
IV	instrumental variable
IVW	inverse-variance weighted
MAF	mean allele frequency
mbQTL	microbiota quantitative trait locus
OR	odds ratio
SCFA	short-chain fatty acid
SM	simple mode
SNP	single-nucleotide polymorphism
UKB	UK Biobank
WM	weighted mode
WME	weighted median