The present disclosure provides methods of producing commodity products, the methods involving culturing a host cell that is genetically modified to produce a uronate dehydrogenase (UDH) that converts a sugar acid to its corresponding 1,5-aldonolactone, that uses NADP+ or NAD+ as a cofactor, and that produces NADPH or NADH, respectively, where the host cell coexpresses an endogenous or a heterologous reductase that utilizes the produced NADPH or NADH to generate the commodity product or a precursor thereof. The present disclosure provides a method of producing downstream products of glycerol and pyruvate in a genetically modified microbial host cell, the method involving culturing a genetically modified microbial host cell of the present disclosure in a culture medium comprising D-galacturonic acid. The present disclosure provides variant UDH polypeptides that utilize NADP+, nucleic acids encoding the variant UDH polypeptides; and host cells genetically modified with the nucleic acids.