Carbohydrate metabolism is a universal function that produces energy and glycan components from monosaccharides such as glucose. If the carbohydrate metabolism enzyme that makes glycan components is congenitally deficient, normal glycans are not synthesized, causing severe systemic diseases [1]. Among these genetic diseases, there are those that show a deficiency of specific sugars, and sugar supplementation therapy is performed. In addition to genetic diseases, changes in glycans are deeply involved in the onset and progression of diseases such as cancer, type 2 diabetes, and neurodegenerative diseases [2–4]. The mechanism by which glycans change is diverse and complex. Abnormal carbohydrate metabolism associated with changes in disease and environment may be involved in changes in glycans, and clarification of the details is awaited [5]. It is the core of glycoscience and an important field.