TABLE 1.

Summary of studies in short chain fatty acids (SCFAs) differentially affect host energy metabolism.

Host	SCFAs	Administered via	Dose	Duration	Main results	References
Mice mesenteric adipocytes	Acetate; butyrate	Incubation	Acetate (0.1 and 0.2 mM); Butyrate (0.2 mM)	–	• Acetate but not butyrate stimulated leptin secretion in wild-type mesenteric adipocytes	Zaibi et al., 2010
Human white adipocytes	Acetate; propionate; butyrate	Incubation	Ranging between 1 μmol/L and 1 mmol/L	–	• Acetate suppressed while butyrate increased basal and the β-adrenergic receptor-mediated glycerol release and propionate did not affect their release	Jocken et al., 2018
Mice	Acetate	Oral	0, 0.3, or 1.5% acetic acid at 10 mL/kg BW	6 weeks	• Acetate increased the expressions of genes for fatty-acid-oxidation- and thermogenesis-related proteins in the liver • No effect on FI	Kondo et al., 2009
Mice	Acetate; propionate; butyrate	Oral	Butyrate (5% w/w); propionate (4.3%); acetate (3.7%)	9 days	• Butyrate and propionate supplementation reduced FI • Acetate increased FI	Lin et al., 2012
Mice	Butyrate	Oral or IV injection	6 M, 0.15 mL for oral 15 mM or 150 mM, 0.1 mL for IV	9 weeks	• Oral rather than intravenous butyrate decreased FI and inhibited orexigenic neuron activity	Li et al., 2018
Mice or rats	Acetate	IP or ICV	IP: 500 mg/kg BW; ICV: 2.5 μmol	Acute	• Significant reduction in acute FI • Acetate may modulate FI through direct impact on the CNS	Frost et al., 2014
Rats	Propionate; butyrate	Oral	5% w/w	10–14 days	• Butyrate and propionate induced IGN via different mechanisms	De Vadder et al., 2014
Rats	Acetate	AT or ICV infusion	AT: 20 μmol kg–1min–1; ICV: 200 μM;	3 days or 4 weeks	• High fat diet induced acetate production • Increased acetate concentrations have been associated with obesity, insulin resistance	Perry et al., 2016b
Pigs	Acetate; propionate; butyrate	Dietary supplementation	0.1% in the diet	28 days	• Acetate reduced FI and body weight gain • SCFAs reduced lipogenesis, enhanced lipolysis via regulating related hormones and genes	Jiao et al., 2020
Humans	IPE	Dietary supplementation	10 g/day	Acute or 24 weeks	• Acute ingestion significantly reduced FI • 24 weeks supplementation reduced weight gain, intrahepatocellular lipid content	Chambers et al., 2015
Humans	Acetate	Distal or proximal colonic supplementation	100 or 180 mmol/l dissolved in 120 ml 0.9% NaCl	3 days	• Distal, but not proximal colonic acetate administration increased fat oxidation and fasting plasma PYY	van der Beek et al., 2016
Humans	IPE	Dietary supplementation	20 g/day	42 days	• IPE supplementation decreased proinflammatory interleukin-8 levels	Chambers et al., 2019

AT, arterial; CNS, central nervous system; FI, food intake; ICV, intracerebroventricular; IGN, intestinal gluconeogenesis; IP, intraperitoneal; IPE, inulin-propionate ester; IV, intravenous; PYY, gut hormones peptide YY.