Table 3. Portal concentrations of individual SCFAs (Acetate, Propionate, Butyrate) by human.

Subjects	(n); age	Treatment	Reported measure	Acetate	Propionate	Butyrate	Unit	References
Died suddenly	6; 16–89 years	Not fasting	Mean	258	88	29	µmol/L	Cummings JH, et al., Gut 1987 28, 1221–7.4)
Surgical patients	5; -	Fasting	Mean	114	32	9	µmol/L	Dankert J, et al., Clin Chim Acta. 1981 110: 301–7.34)
Surgical patients	28; 23–74 years	Fasting	Mean	128	34	18	µmol/L	Peters SG, et al., Gut. 1992 33: 1249–52.35)
Surgical patients	10; -	Fasting 10 g Lactulose was injected into the caecum at surgery (Peak value)	Mean	241	39	27	µmol/L	Peters SG, et al., Gut. 1992 33: 1249–52.35)
Surgical patients	6; -	Fasting 6.7 g Lactulose was injected into the caecum at surgery (Peak value)	Mean	166	31	22	µmol/L	Peters SG, et al., Gut. 1992 33: 1249–52.35)
Surgical patients	7; 54–73 years	Fasting	Mean	236	18	26	µmol/L	van der Beek CM, et al., J Nutr. 2015 145: 2019–24.36)
Surgical patients	7; 54–73 years	Fasting butyrate: 100 mmol/L; 60 mL enema at surgery (Peak value)	Mean	NR	NR	92	µmol/L	van der Beek CM, et al., J Nutr. 2015 145: 2019–24.36)

Mean, the mean value; NR, not reported