5-HT	5-Hydroxytryptamine
BDNF	Brain-Derived Neurotrophic Factor
CNS	Central Nervous System
ENS	Enteric Nervous System
EEC	Enteroendocrine Cells
FMT	Fecal Microbial Transplantation
GABA	Gamma Aminobutyric Acid
GD	Gut Dysbiosis
GF	Germ Free
GBA	Gut–Brain Axis
GI	Gastrointestinal
GM	Gut microbiota
HPA	Hypothalamus–Pituitary–Adrenal Axis
IFN-γ	Interferon-γ
IL-1β	Interleukin-1β
IL-6	Interleukin-6
IBS	Inflammatory Bowel Syndrome
IRS	Inflammatory Response System
JB-1	Lactobacillus Rhamnosus
LPS	Lipopolysaccharide
MAMPs	Microbe Associated With Molecular Patterns
MDD	Major Depressive Disorder
NOD	Nucleotide-Binding Oligomerization Domain-Containing Protein
SCFAs	Short-Chain Fatty Acids
TLRs	Toll-like Receptors
TNF-α	Tumor Necrosis Factor-A