Composition (I) comprises crystalline xylose isomerase (EC 5.3.1.5) and at least one salt of a metal and/or alkaline earth metal. An independent claim is included for preparing (I) comprising: crystallizing the xylose isomerase in the presence of at least one salt of alkaline earth metal and/or metal； drying the crystallized xylose isomerase and optionally pulverizing, and formulating as a pharmaceutical dosage form comprising gastric juice resistant-pellet, -tablet, -capsule, -granules or -powders. ACTIVITY : Anabolic； Metabolic； Gastrointestinal-Gen. MECHANISM OF ACTION : None given.
