抄録
Feces protein particles (FPP), spherical or oval in shape, 1.0_??_3.5 μ in diameter, which were observed in the fresh feces of the Japanese, in an average density of 5×109/g, resembled the rice protein bodies (RPB) in electron-microscopical fine structure. The FPP decreased in the feces of the man who had been given a rice-free diet consisting of steamed sweet potato; when boiled rice had been fed, the FPP increased, and reached the level of the original density within 5 days. The FPP were concluded to be derived from an indigestible fraction of the RPB which were supplied to the Japanese with the daily intake of rice.