5-FU	5-Fluorouracil
BCAAs	Branched-Chain Amino Acids
CD4+	Cluster of Differentiation 4 Positive
CD8+	Cluster of Differentiation 8 Positive
DCs	Dendritic Cells
CSF	Cerebrospinal Fluid
EBV	Epstein–Barr Virus
ERK	Extracellular Signal-Regulated Kinase
GI	Gastrointestinal
HBV	Hepatitis B Virus
HCV	Hepatitis C Virus
HIV	Human Immunodeficiency Virus
HMDB	Human Metabolome Database
HPV	Human Papilloma Virus
HSV	Herpes Simplex Virus
IBS	Irritable Bowel Syndrome
IAld	Indole-3-aldehyde
IGE	Immunoglobulin E
IL	Interleukin
ImP	Imidazole Propionate
IPA	Indole-3-propionic Acid
LBP	LPS Binding Protein
LOS	Lipooligosaccharides
LPS	Lipopolysaccharides
LUSC	Lung Squamous Cell Carcinoma
MAPK	Mitogen-Activated Protein Kinases
NAFLD	Nonalcoholic Fatty Liver Disease
NK	Natural Killer
OTU	Operational Taxonomic Unit
PCR	Polymerase Chain Reaction
PD-1	Programmed Cell Death 1
PI3K	Phosphoinositide 3-Kinase
RBC	Red Blood Cells
ROS	Reactive Oxygen Species
rRNA	Ribosomal RNA
SCFAs	Short-Chain Fatty Acids
TB	Tuberculosis
TLR	Toll-Like Receptor
TLR4	Toll-Like Receptor 4
TMAO	Trimethylamine N-Oxide
TNF	Tumor Necrosis Factor
TP53	Tumor Protein p53
Tregs	Regulatory T-Cells
WBC	White Blood Cells