Type 2 Diabetes Intervention by Gut Microbiota-directed Diet -a Open Labelled RCT

Inclusion Criteria: * Newly diagnosed type 2 diabetes mellitus patients who have been diagnosed or screened for treatment without any hypoglycemic drugs; * 6.5%≤HbA1c≤8.5%； * FPG\<10.0mmol/L; * BMI≥24； Exclusion Criteria: * suspected other types of diabetes * Moderate stroke occurred within one year; * Frequent diarrhea or constipation in the past 3 months (more than 4 times / week); * Acute complications occurred in the past 3 months, such as infection, ketosis and acidosis; * Pregnant and lactating women (or women who are currently trying to conceive, or who are likely to have children and do not use contraceptives); * Drinking (1 weeks of drinking more than 5 times, on average 2 two Baijiu or half Jin of yellow wine or 5 bottles of beer above); * Those who have received drug treatment for the following diseases in the past three months: cholecystitis, peptic ulcer, urinary tract infection, acute pyelonephritis, cystitis, hyperthyroidism and other thyroid dysfunction; * Gastrointestinal surgery (except appendicitis and hernia surgery); * Antibiotics have been used in the past 3 months for 3 days or more; * Physical methods, such as liposuction or gastrointestinal reconstruction, have been used to lose weight in the past 3 months; * Physical disability, or inability to take care of themselves, recall and answer questions clearly due to other reasons; * Anemia: hemoglobin \< 10g / dl; * Patients with severe liver diseases such as chronic hepatitis, persistent hepatitis and cirrhosis, and hepatitis B virus surface antigen (HBsAg) positive and abnormal liver function (serum alanine aminotransferase and aspartate aminotransferase are 2.5 times the normal value). * Other serious diseases, such as malignant tumors, serious mental diseases, serious infectious diseases, etc; * Patients who are participating in other intervention studies; * In the judgment of the study physician, there are any conditions that affect the study compliance, such as:Alcohol or drug abuse in the past 12 months; Serious adverse drug treatment compliance in the past 12 months; The residence is far away from the research center, or it is planned to move far away or travel frequently in the next year; The clinical diagnosis of dementia or the judgment of cognitive function by the research physician will affect the research compliance; Other medical, psychological or behavioral factors that affect the study compliance are judged by the study physician.