Phaseolus vulgaris L. Leaves Increase Short-Chain Fatty Acid (SCFA) Production, Ameliorating Early Metabolic Alterations.

High-fat/high-fructose diets promote early metabolic disorders in weight and lipid and glucose metabolism. Bioactive compounds such as polyphenols and fiber present in plant-based food prevent the development of metabolic disorders. The objective of the present study was to evaluate the effect of Phaseolus vulgaris L. Flor de Mayo Eugenia (FME) bean leaves on early metabolic alterations in male Wistar rats fed a high-fat/high-fructose diet. After proximate and chemical analysis of FME bean leaves, thirty-six male Wistar rats (ethical approval 06FCN2019 and 77FCN2019) were randomly assigned to one of four groups: 1) standard diet (S) fed with Rodent Laboratory Chow 5001®; 2) standard diet + 10% dry FME bean leaves (SBL); 3) high-fat (lard) and high-fructose diet (H); and 4) high-fat/high-fructose diet + 10% dry FME bean leaves (HBL). The study was carried out for six weeks. Group H exhibited early metabolic alterations compared to Group S: final weight gain (↑15%), abdominal fat accumulation (waist circumference, ↑11%), triglycerides (↑30%), glucose (↑16%), insulin resistance (HOMA-IR, ↑32%), and fecal triglycerides (↑284%) and decreased total short-chain fatty acids (SCFAs, ↓17%). FME bean leave supplementation (HBL) prevented body weight gain (↓12%), abdominal fat accumulation (waist circumference, ↓10%), and early insulin resistance (glucose area under the curve, ↓6%) compared to Group H. The supplementary bean leave diet increased SCFA production (↑54%), most likely mediated by the fiber and polyphenols present in the leaves. Therefore, bean leaves are a low-cost alternative for human nutritional care and prevention of early metabolic alterations.