Evaluate the effects of pasteurized Akkermansia muciniphila Akk11 (killed bacteria) capsules compared to placebo on body composition parameters (including weight, BMI, body fat percentage, waist - hip ratio (WHR), wrist circumference, visceral fat area, and basal metabolic rate) and blood lipid levels (total cholesterol (TC), low - density lipoprotein (LDL), high - density lipoprotein (HDL), and triglycerides (TG)) in overweight or obese adults.

Inclusion Criteria:

1. A body mass index (BMI) of 24 kg/m² or above;
2. Voluntarily signing an informed consent form to take part in the study;
3. Willingness to undertake the study protocol and associated restrictions, such as adhering to a calorie - restricted - low carbohydrate diet;
4. No intention to become pregnant from 14 days before screening, and commitment to using effective contraception until six months after the trial concludes.

Exclusion Criteria:

1. Intake of products akin to the test product in the recent period that might sway the outcomes;
2. Presence of mental or neurological disorders, celiac disease, lactose intolerance, or allergic conditions;
3. Being pregnant, breastfeeding, or planning to conceive;
4. Past diagnosis of Irritable Bowel Syndrome, Ulcerative Colitis, Hepatic Cirrhosis, or Diabetes Mellitus;
5. Use of antibiotics in the preceding three months;
6. Inability to comply with the test product regimen or attend follow-up visits regularly, making efficacy assessment unfeasible;
7. Smoking in excess of 10 cigarettes daily;
8. Hypersensitivity to probiotic products;
9. Any other participants deemed unsuitable for the research by the investigator.