2. Introduction:
*  GOS (galato-oligosaccharide) is composed of a mixture of de- to penta-galactooligosaccharides with galactosyllactose, a constituent of human breast milk;
*  GOS (galato-oligosaccharide) also includes lactose and monosaccharides;
*  GOS (galato-oligosaccharide) promotes the growth of bifidobacteria and lactic acid bacteria, which are helpful microorganisms found in the intestines and contribute to the health of the gastrointestinal tract;
*  GOS (galato-oligosaccharide) is soluble and extremely resistant to acid and heating during food processing;
*  GOS (galato-oligosaccharide) is widely used by the food industry worldwide, especially in infant formula, yoghurt, smoothies and beverages for gut health, fibre enhancement and calcium.

3. Physiological Effects:
1).  Indigestibility and low energy value;
2). Bifidobacteria proliferation factor, and promote intestinal peristalsis, prevent constipation and diarrhea;
3). Promoting the body's absorption of calcium, magnesium, iron and other minerals;
4). Promoting bone growth and development, and preventing from osteoporosis;
5). Promotion of natural vitamins and folic acid formation, enhancing immunity and resistance to disease;
6).  Not causing obesity, dental caries and is an ideal functional sweeterner with low calorific value;
7). Better mprovement of high blood lipids, hypertension and arteriosclerosis and other cardiovascular diseases;
8).  Focusing on milk intolerance group.