Inclusion Criteria:  Male; 18 to 35 years old; BMI≥28kg/m2; No contraindications for MRI examination; No alcohol intake, no use of any probiotic-related foods or medications, antibiotics, hormones and weight-loss products in the past three months; No other metabolic diseases; Volunteering to participate in and cooperate with the research and sign the written informed consent.  Exclusion Criteria:  Subjects suffered from Secondary obesity including hypercortisolism, hypothyroidism, insulinoma, drug-induced obesity, etc. Obesity-related complications that may be life-threatening or cause serious consequences in the short term have occurred.  Any of the following cardiovascular diseases have occurred in the past：  Myocardial infarction. Cerebral infarction. Cardiac or revascularization surgery such as coronary artery bypass graft surgery and percutaneous transluminal coronary angioplasty. Unstable angina pectoris; Congestive heart failure diagnosed as Class III or IV of the New York Heart Association. Transient ischemic attack or significant cerebrovascular disease. Patients with symptoms of gastrointestinal diseases, including intestinal obstruction, intestinal ulcer and gastrointestinal bleeding. A history of gastrointestinal surgery, such as bariatric surgery, banding surgery, gastrointestinal anastomosis and enterectomy. A state of known immunodeficiency, including but not limited to individuals who have experienced organ transplantation or acquired immunodeficiency syndrome (AIDS). Subjects who cannot comply with the protocol and patients with serious physical or psychological diseases that may affect the effectiveness or safety under the judgment of the investigator. Patients who cannot cooperate to complete the entire intervention and follow-up due to various other factors.