Table 1.

SCFA levels in humans.

Metabolite	Localization	Concentration	References
Total SCFAs	Caecum	131 mmol/kg (dry weight)	[42,43]
	Portal	323–375 µmol/L
	Hepatic	148–238 µmol/L
	Blood	79–184 µmol/L

Data from two studies. The oldest used 6 subjects, one aged 16 and the remaining five aged 36–89 [42]; 22 individuals aged 30–78 participated in the newer report [43].