The goal of this clinical trial is to learn about, test, and compare health outcomes of curcumin supplementation (400 mg). Two primary hypotheses are:

1. Curcumin supplementation will improve glycemic control in older adults with pre-diabetic conditions over a 12-week period.

   * Rationale: Curcumin has been shown to enhance insulin sensitivity, reduce fasting blood glucose, and lower HbA1c levels in preclinical and clinical studies. This hypothesis will be tested by measuring changes in fasting glucose, insulin levels, and diabetic biomarkers from baseline (Week 0) to Week 12.

2. Curcumin supplementation will beneficially alter gut microbiota composition and diversity, which is associated with improved metabolic outcomes in older adults with pre-diabetes.

   • Rationale: Curcumin is known to possess prebiotic-like properties and can influence gut microbial populations. By analyzing stool samples using metagenomic sequencing, this hypothesis will evaluate whether curcumin intake leads to increased abundance of beneficial bacteria (e.g., Akkermansia, Faecalibacterium) and decreased pathogenic taxa, alongside improved metabolic markers.

Inclusion Criteria:

• To be eligible, participants were required to meet at least one of the following criteria: a) Prediabetes, defined as a fasting blood glucose level of 100-125 mg/dL or an HbA1c of 5.7-6.4%, or b) A body mass index (BMI) ≥25.

Exclusion Criteria:

• a) A preexisting cardiometabolic condition such as diabetes, b) Liver disease, c) De-mentia, d) Tobacco use within one year prior to the study, and e) Use of medications targeting diabetes or blood lipids.