A nutrient composition, a lipid metabolism-improving agent, and prophylactic and/or therapeutic agents typically for inflammatory bowel diseases, immune disorders, cancers, non-alcoholic steatohepatitis, obesity, diabetes, and hypercholesterolemia each contain a cellulose acetate having a total degree of acetyl substitution of 0.4 to 1.1. The cellulose acetate may be one having a compositional distribution index (CDI) of 2.0 or less, where the CDI is defined by the formula: CDI = Measured value of half height width of chemical composition / ( Theoretical value of half height width of chemical composition ) where the measured value of half height width of chemical composition represents a half height width of chemical composition determined by HPLC analysis of a cellulose acetate propionate prepared by propionylating all residual hydroxy groups of the cellulose acetate (sample), and the theoretical value of half height width of chemical composition = 2.35482 3 ˆ— DPw ˆ— DS / 3 ˆ— 1 ˆ’ DS / 3 / DPw where DS is the total degree of acetyl substitution and DPw is a weight-average degree of polymerization determined by a GPC-light scattering method using a cellulose acetate propionate prepared by propionylating all residual hydroxy groups of the cellulose acetate (sample).
