Table 2.

Studies of gut microbiota-related short-chain fatty acids in nonalcoholic fatty liver disease.

Conditions		Treatment	Main Results	Ref.
Animal	Polysaccharide- rich diet	Gpr41 knockout	[↑]Intestinal transit rate, unabsorbed SCFAs [↓]Weight gain, total body fat, PYY	[60]
	Methionine- and choline-deficient diet	Acetate, propionate, butyrate	[↑]AMPK activation, CPT1a [↓]ALT, AST, lipid droplets, triglyceride, cholesterols, steatosis, inflammation, hepatic aggregation of macrophages	[62]
	High-fat diet	Acetate, propionate, butyrate	[↑]Fatty acid oxidation, insulin sensitivity, phospho-AMPK, phospho-ACC [↓]Steatosis, PPARγ expression and activity	[63]
		-	[↑]Propionate and butyrate in blood, SCFA-producing bacteria [↓]Endotoxin-secreting bacteria, proinflammatory cytokines	[61]
		-	[↑]Hepatic GLP-1, phospho-AMPK, phospho-ACC, IR, IRS-1 [↓]Steatosis	[67]
		-	[↑]Christensenellaceae, Blautia, Lactobacillus, ZO-1 [↓]Weight gain, endotoxins, TLR4, Myd88, CCL2, TNFα, IL-2, IL-6, IFNγ, triglyceride, cholesterol, ALT, AST	[69]
Human	NAFLD	-	[↑]Fecal acetate and propionate, Fusobacterium, Prevotella, Eubacterium biforme, T helper 17 cell/resting regulatory T cell ratio in peripheral blood mononuclear cell [↓]Resting regulatory T cells	[58]

↑ indicates an increase in condition, ↓ indicates a decrease in condition. SCFA, short-chain fatty acid; PYY, peptide-YY; AMPK, AMP-activated protein kinase; CPT1a, carnitine palmitoyltransferase 1a; ALT, alanine aminotransferase; AST, aspartate transaminase; ACC, acetyl-CoA carboxylase; PPARγ, peroxisome proliferator–activated receptor-γ; GLP-1, glucagon-like peptide 1; IR, insulin receptor; IRS-1, insulin receptor substrate 1; TLR4, Toll-like receptor 4; CCL2, C-C motif chemokine 2; TNFα, tumor necrosis factor α; IL-2, interleukin 2; IL-6, interleukin 6; IFNγ; interferon γ; NAFLD, nonalcoholic fatty liver disease.