Prediabetes is a metabolic condition characterized by elevated blood glucose levels that are higher than normal but below the diagnostic threshold for diabetes. Early intervention to improve glycemic control may help delay the progression to type 2 diabetes. Momordica charantia (bitter melon) peptides have been reported to possess potential glucose-regulating effects.

This study aims to evaluate the effects of BmpP® bitter melon peptide supplementation on glycemic control in adults with prediabetes. This study is designed as a 12-week single-arm, open-label clinical trial. Approximately 12 adults aged 30-65 years with prediabetes will be recruited. Participants will consume bitter melon peptide capsules three times daily before meals for 12 weeks.

Primary outcomes include fasting blood glucose, postprandial glucose response, and HbA1c levels. The findings of this study may provide preliminary evidence regarding the potential role of bitter melon peptides in blood glucose regulation.

Inclusion Criteria:

• Adults aged 30-65 years, both male and female.

• Participants meeting any of the following criteria for prediabetes:

  1. Fasting blood glucose 100-125 mg/dL
  2. HbA1c 5.7-6.4%
  3. Previous clinical records indicating 2-hour OGTT glucose levels of 140-199 mg/dL

• Body mass index (BMI) between 24-35 kg/m², with waist circumference recorded (men ≥90 cm; women ≥80 cm).

• Stable lifestyle (including diet, physical activity, and sleep habits) during the past three months.

• No use of blood glucose-regulating supplements prior to or during the study.

• Willingness to comply with study procedures and complete all required assessments.

• Provision of written informed consent.

Exclusion Criteria:

• Diagnosis of type 2 diabetes mellitus (HbA1c ≥6.5% or physician diagnosis).
• Current use of antidiabetic medications (e.g., metformin, DPP-4 inhibitors, SGLT2 inhibitors, GLP-1 receptor agonists, or insulin).
• Use of medications that may affect blood glucose levels, such as corticosteroids, antipsychotic drugs, or unstable thyroid medications.
• Presence of severe hepatic, renal, cardiovascular diseases, active cancer, or gastrointestinal malabsorption disorders.
• Pregnant or breastfeeding women, or those planning to become pregnant.
• Body weight change exceeding ±5% within the past three months, or currently following a weight-loss program or special diet.
• History of alcohol abuse or substance misuse.
• Individuals engaged in night shift or rotating shift work.
• Known allergy to any component of the study product.
• Participation in another clinical trial within the past 1 month, or antibiotic use within the past 8 weeks (if gut microbiota analysis is involved).
• Individuals who are students currently taught by Associate Professor You-Cheng Shen or Dr. Jing-Bin Lin, or laboratory staff, assistants, or employees with a supervisory or subordinate relationship with the investigators.