Effects of Milk Powder Intervention on Blood Glucose Control and Fluctuation in Middle-aged and Elderly People With Pre-diabetes

Inclusion Criteria: 1. Age between 40 and 75 years, regardless of gender. 2. Impaired fasting glucose (5.6 mmol/L ≤ FPG \< 6.9 mmol/L) or glycated hemoglobin (HbA1c) between 5.7-6.4% (39-47 mmol/mol). 3. Resided in Guangzhou for the past six months and no plans to relocate or travel outside the city in the next month. 4. Signed informed consent form and voluntarily agreed to participate in the project. Exclusion Criteria: 1. Patients with a confirmed diagnosis of diabetes who are currently taking glucose-lowering medications (e.g., insulin, GLP-1 receptor agonists, or SGLT2 inhibitors). 2. Individuals with lactose intolerance or dairy product intolerance. 3. Pregnant, planning to become pregnant within the next three months, or currently breastfeeding. 4. Weight change \> 5% in the past three months or plans to lose weight or change dietary habits. 5. Alcohol consumption \> 40g/day. 6. Individuals with communication barriers, cognitive impairments, or other conditions that may prevent them from completing the study procedures. 7. Severe diseases that may affect participation in the study, including but not limited to endocrine disorders, severe cardiovascular or cerebrovascular diseases, cancer, metabolic diseases, etc. 8. Participation in or current involvement in other clinical trials within the past three months. 9. No use of antibiotic medications within the past three months.