Figure 1.

The synthesis pathway of SCFAs. Acetate, propionate and butyrate are main SCFAs produced by dietary fibers of microbial fermentation in gut. Production of acetate involves in pyruvate by Acetyl-CoA and Wood-Ljungdahl pathway. Butyrate is synthesized from Acetyl CoA that is subsequently reduced to Butyryl-CoA, which can be converted to butyrate by so-called classical pathway via Butyryl-phosphate. Propionate can be formed from succinate that is converted to methylmalonyl-CoA by succinate pathway. Furthermore, as a precursor lactate also participate the synthesis of propionate by acrylate pathway.