Provided is a composition for improving intestinal microecology and preventing a chronic disease, comprising inulin, galacto-oligosaccharide, and a dietary fiber complex in a ratio of 1-75:1-75:5-95, preferably 10-50:10-50:25-50. Provided is a balanced nutritious food, comprising cereal powder and the composition in a ratio of 50-95:50-5, preferably 70-95:30-5. Also provided is an application of the composition in preparing a food or drug for preventing inflammatory bowel disease, improving gastrointestinal motility and preventing constipation, preventing diabetes, preventing cardiovascular and cerebrovascular diseases, or regulating gut flora to improve immunity.
