This single-arm clinical trial investigates the effects of daily durian consumption on the gut microbiome, host metabolome, and glucose metrics in adults with type 2 diabetes mellitus (T2DM). Forty adults with T2DM will undergo a pre-durian phase, a durian consumption phase, and a post-durian phase, each lasting 10 to 14 days. Participants will attend five visits at Singapore General Hospital for clinical assessments, continuous glucose monitoring, fasting blood collection, stool sample collection, and dietary and stool record submission. The study aims to determine whether durian consumption alters microbiome and metabolomic profiles and whether it affects glycemic measures in adults with T2DM.

Durian is a widely consumed tropical fruit with high fiber content and multiple bioactive compounds, including phenolics, flavonoids, carotenoids, and volatile sulfur compounds. Although animal and limited human studies suggest possible metabolic effects, the impact of durian consumption on gut microbiota and host metabolomic profiles in adults with type 2 diabetes mellitus remains unclear. This single-arm interventional study will enroll 40 adults with T2DM at Singapore General Hospital. Participants will complete five study visits over approximately 1.5 to 3 months. After screening, eligible participants will enter a pre-durian phase, a durian phase, and a post-durian phase, each lasting 10 to 14 days. During the durian phase, participants will consume 100 g of durian on Day 1 and 200 g daily from Day 2 onward for 10 to 14 days. Continuous glucose monitoring will be performed across study phases. Blood samples will be analyzed for clinical laboratory parameters, inflammatory markers, metabolomics, and genetic/epigenetic analyses. Stool samples will undergo metagenomic sequencing and metabolomic analysis. The study hypothesis is that durian consumption will result in significant changes in the gut microbiome and metabolome of individuals with T2DM without adversely affecting gluometric measures.

Inclusion Criteria:

1. Age 21 to 70 years.
2. Diagnosis of type 2 diabetes mellitus.
3. Agrees to consume durian for 2 weeks.
4. Body mass index 25 to 40 kg/m².

Exclusion Criteria:

1. Known or suspected intolerance or allergy to durian.
2. Known skin reaction to adhesives used in a continuous glucose sensor.
3. Uncontrolled diabetes (HbA1c greater than 8.5%).
4. Severe hypertriglyceridemia (triglycerides greater than 4.5 mmol/L).
5. Smoking.
6. Previous gastrointestinal surgeries, including cholecystectomy, gastrectomy, bariatric surgery, or colectomy.
7. Inflammatory bowel disease.
8. Glomerular filtration rate less than 30 mL/min.
9. ALT greater than 3 times upper limit of normal.
10. AST greater than 3 times upper limit of normal.
11. Liver cirrhosis.
12. Significant alcohol consumption, defined as more than 20 g/day for women and more than 30 g/day for men.
13. Pregnant, breastfeeding, or intending to conceive during the study.
14. Current hemorrhoids or piles causing rectal bleeding during stool passage.
15. Systemic steroid use.
16. Insulin use.
17. Weight loss medications, including GLP-1 receptor agonists, orlistat, or phentermine.
18. Antibiotic, prebiotic, probiotic, vitamin C, or traditional Chinese medicine use in the last 1 month.
19. Uncontrolled thyroid disease.
20. Any factor likely to limit adherence to study protocol, including dementia, substance abuse, poor appointment adherence, or family concerns regarding participation

To comply with the institution's policy. Additional research sharing agreement would be needed