A fermented functional food enriched in phytosterol and carotenoids improves lipid profile and insulin resistance and restores vitamin A status in high-fat diet-induced metabolic syndrome rats†

Tackling metabolic syndrome (MetS) using functional fermented food has recently attracted much attention. A vegetable-fermented maize - and fruit-based probiotic functional food (maize 5% and fruits 30%) was previously designed, which was enriched in papaya/melon carotenoids and dispersible phytosterols to obtain a cholesterol-lowering effect. The aim of this work was to investigate the effect of this new functional food on an HFD (high-fat diet)-induced MetS rat model focusing on lipid and glucose metabolic disorders and considering vitamin A status. Male Sprague-Dawley rats (n = 36) were randomly divided into 4 groups (n = 9): a control group (C); an HFD group; and two HFD groups receiving 1.44 g per rat per day of the functional fermented food during the three months of the experiment following a preventive (HFD-P) or a curative (HFD-C) mode. The intake of the functional food decreased the adipose tissue amount by 1.5 times in preventive and curative mode groups and restored their LDL cholesterol and triglyceride levels to C level. The area of hepatic lipid droplets was reduced in both HFD-P and HFD-C groups compared with HFD group, which was associated with a reduction in inflammation and lipid oxidation. Both the HFD-P and HFD-C groups alleviated HFD-induced insulin resistance, as evidenced by the return of fasting insulin levels and the HOMA-IR index to control levels. However, only the HFD-C group improved the glucose tolerance test and skeletal muscle insulin sensitivity. Notably, alteration in vitamin A status in HFD rats was restored with HFD-C and HFD-P. Altogether, these results support the potential of this nutritional strategy to prevent MetS.