NMR	Nuclear magnetic resonance
MS	Mass spectroscopy
CE	Capillary electrophoresis
GC	Gas chromatography
HPLC	High pressure liquid chromatography
LC	Liquid chromatography
UPLC	Ultra-performance liquid chromatographic
GCxGC-TOF-MS	Two-dimensional gas chromatography–time-of-flight mass spectrometry
PCA	Principal component analysis
PLS-DA	Partial least squares discriminant analysis
OPLS-DA	Orthogonal PLS-DA
PCs	Principal components
BCAA	Branched chain amino acid
SCFAs	Short-chain fatty acids
BCFAs	Branched chain fatty acids
CO2	Carbon dioxide
CH4	Methane
H2S	Hydrogen Sulfide
AFLD	Alcoholic fatty liver disease
NAFLD	Non-AFLD
NASH	Non-alcoholic steatohepatitis
HCC	Hepatocellular carcinoma
GCDCA	Glycochenodeoxycholic acid
LPC	Lysophosphatidylcholine
Ref	References