Table 2.

Receptors for main SCFAs, showing half maximal effective concentrations (EC50) obtained using different cell lines with appropriate transfected proteins.

Metabolite	Receptor	EC50	References
Acetate	GPR 41	1.02–2.99 mM	[50,51,53,56,61]
	GPR 43	52 µM–4.46 mM
	GPR 109A	>10 mM
	OR51E2	2.93 mM
Propionate	GPR 41	11.6 µM–5.21 mM
	GPR 43	31 µM–4.85 mM
	GPR 109A	>10 mM
	OR51E2	~100 µM–2.16 mM
Butyrate	GPR 41	158 µM–4.38 mM
	GPR 43	100 µM–4.55 mM
	GPR 109A	1.6 mM
	OR51E2	unknown