Soy-derived hydrolysed peptides prevent diet-induced insulin resistance through modification of the gut microbiota and inflammation in mice

This study aimed to evaluate the effects of soy-derived hydrolysed peptides (SPEP) and soy-derived proteins (SPRO) on diet-induced insulin resistance. Purposely, male C57BL/6 mice were randomly assigned to four groups and maintained on their respective diets for 16 weeks: (1) normal chow diet (NCD), (2) high-fat diet (HFD), (3) HFD + SPRO, and (4) HFD + SPEP. SPEP treatment significantly decreased the fasting serum glucose (3.70 mmol L^-1, 46.93%), and HOMA-IR (1.75, 46.17%), compared to HFD group. Furthermore, SPEP intervention significantly reduced hepatic serum low-density lipoproteins cholesterol, lipopolysaccharides, leptin, and interleukin-6 levels, while the liver total bile acids increased by 74.43%, compared to HFD group. SPEP intervention resulted in a low abundance of obesity and insulin resistance-associated microbes (<i>Oscillospira</i> and <i>Ruminococcus</i>), and a high abundance of anti-inflammation-related bacteria (<i>Akkermansia</i> and <i>F16</i>), compared to HFD group. This study's findings suggested that SPEP was more effective than SPRO in preventing insulin resistance.