This study is a randomized, open labelled, placebo-controlled clinical trial. The main purpose is to verify the superior effect of gut microbiota directed diet intervention over standard diet intervention by evaluating the changes of HbA1c relative to baseline at 16 weeks and 28 weeks of follow-up.

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.