The low-poly xylose, also known as xylosaccharide, is a functional polymerase made from 2-7 xylitol molecules with beta-1, 4 glycosides. Compared with commonly used soybean oligosaccharides, oligosaccharides, oligosaccharides, etc., it can selectively promote the proliferation activity of bifidobacterium. Its bifidofactor function is 10 to 20 times that of other polysaccharides.