Several enzymes are involved in the incorporation of these substrates in the gluconeogenesis pathway [3]: lactate dehydrogenase (LDH) for lactate; glycerol kinase (GK) and glycerol-3-phosphate dehydrogenase (GPD) for glycerol; and acyl-CoA synthetase short-chain family member 3 (ACSS3), propionyl-CoA carboxylase (PCC), methylmalonyl-CoA epimerase (MCEE), and methylmalonyl-CoA mutase (MUT) for propionate.