Practically no starch has been found in mature soybean seeds and their main oligosaccharides are sucrose, stachyose and raffinose. However the presence of enzymes which catalyze the hydrolysis of these oligosaccharides except sucrose in digestive juices of higher animals has not been reported. To examine the utilization of soybean oligosaccharides by the higher animals, the following experiments were carried out: the balance study of soybean carbohydrates with intact rats, the time study of the disappearance of soybean oligosaccharides from the gastro-intestinal tracts and the effect of antibiotics on the utilization of the carbohydrates.
From these experiments it was indicated that about 90% of soybean oligosaccharides were absorbed and that in the presence of antibiotics, however, absorption of the carbohydrates reduced to 52%. These results imply the soybean oligosaccharides are digested mainly by the intestinal microflora and utilyzed pretty well by the higher animals. However, the utilization of soybean carbohydrates were much slower than sucrose and remained longer time in cecum and other intestines.