Moringa oleifera (MO) is a traditional food in tropical and subtropical areas and has attained a growing interest for its medicinal properties. It's a nutrient-rich vegetable, high in protein and polyphenol content. The MO dry leaves and leaf extracts have been shown to exert numerous in vitro activities and in vivo effects, including the hypoglycemic effect. Thus, MO could be an alternative to prevent or treat diabetes. Studies in humans, however, are still limited. This proposal aims to study the efficacy of Moringa oleifera to improve the control of glycaemia in subjects with prediabetes. A 3-month dietary intervention with MO dry leave capsules will be performed and compared to placebo.

The tree Moringa oleifera (MO) is a traditional medicinal plant in tropical and subtropical areas, also consumed as food, which is currently expanding worldwide as a protein-rich leafy vegetable and for the medicinal value of its phytochemicals, in particular its glucosinolates. Specifically, MO dry leaves and leaf extracts have been shown to exert numerous in vitro activities and in vivo effects, including the hypoglycemic effect. Thus, MO could be an alternative to prevent or treat diabetes. In this sense, in vitro and preclinical experiments have shown that MO could potentially reverse some of the pathophysiological manifestation of diabetes and its comorbidities, such as hepatic fat accumulation and insulin resistance, oxidative stress, inflammation and peripheral hyperglycemia. Studies in humans, however, are still limited. This proposal aims to study the efficacy of Moringa oleifera to improve the control of glycaemia in subjects with prediabetes. A 3-month dietary intervention with MO dry leave capsules will be performed and compared to placebo. This will be a double-blind, randomized, placebo controlled, parallel group intervention study. Subjects will randomly consume either 6 capsules of dry MO leaves (400 mg dry leaf powder /capsule) or 6 placebo capsules per day during 3 months. The study subjects will provide samples for outcome measurements at three different time points: basal, 6 weeks and 12 weeks of supplementation. Glycaemia and plasma inflammatory and metabolic markers will be measured, as well as the gut microbiota composition.

Inclusion Criteria:

• Prediabetes: HbA1c between 5.7-6.4 % or fasting blood glucose between 100 - 125 mg/dl or impaired glucose tolerance (> 140 mg/dl and < 200 mg/dl two hours post oral challenge).
• No pharmacological treatment prescribed for glycemia control.

Exclusion Criteria:

• Diabetes Mellitus
• Impaired renal function: < 60% Glomerular filtration
• Uncontrolled high blood pressure
• Previous cardiovascular events or coronary disease
• Autoimmune disease
• HIV
• Severe gastrointestinal disease
• Cancer
• Psychiatric illness
• Elevated liver enzymes (x2 normal range)
• Alcohol abuse (higher than 14 and 21 doses/week for women and men, respectively)
• Morbid obesity (BMI>35kg/m2)
• Pregnancy
• Pharmacological treatments that interfere with glucose control.

Although a specific plan has not been conceived yet, sharing research data is a good practice that the investigators would pursue at due time.

One member of the research team was in charge of product preparation and delivery to the participants following the randomization list.