The present invention relates to a novel method for producing metabolites from omeprazole using bacterial cytochrome P450, and a composition therefor, and more specifically, to a composition and a kit for producing a 5′-hydroxyl product from omeprazole, containing bacterial cytochrome P450 BM3 (CYP102A1) or mutants thereof, and to a method for producing the same. The composition, the kit, and the method are capable of economically and highly efficiently mass-producing the 5′-hydroxyl product from the omeprazole, and thus will significantly contribute to development of a novel drug using metabolites from the omeprazole.