An interventional study was conducted in collaboration with the Catholic University of San Antonio Murcia (UCAM). A total of 21 prediabetic volunteers (fasting blood glucose levels between 100 and 120 mg/dL) who were not taking diabetes medication or antibiotics during the study were recruited. Pregnant or lactating women were also excluded.
The participants were invited to an information session to learn more about the study objectives and procedures, and they signed informed consent forms. During this first visit, anthropometric measurements were taken, and a questionnaire was administered to gather information about their diet and physical activity. Each volunteer made four more visits to the UCAM facilities. On each visit, the volunteers ingested either a placebo capsule or the formulated dietary supplement, followed by a standard breakfast consisting of three toasted bread slices and two single-serving packets of strawberry or peach jam (resulting in a total carbohydrate intake of 49.5 g). The volunteers were randomly assigned to receive the placebo or the supplemet and each of them was taken twice. At time 0 and at different times after breakfast intake (15, 30, 45, 60, 75, 90, 105 and 120 min) blood glucose was measured using capillary blood sample obtained by finger prick and a glucometer.
