Hemp Seed Protein-Derived Lipase Inhibitory Peptides Attenuate High-Fat Diet-Induced Obesity: Evidence from Intestinal Fat Digestion and Gut–Liver Axis Regulation

Obesity and its metabolic complications represent a major global health challenge, and food-derived bioactive peptides are emerging as promising dietary interventions. In this study, two hemp seed protein-derived tetrapeptides with pancreatic lipase (PL) and cholesterol esterase (CE) inhibitory activity, APAM and RLPA, were co-administered with a high-fat diet (HFD) to male C57BL/6J mice at 25 and 100 mg/kg body weight for 10 weeks. Both peptides dose-dependently alleviated HFD-induced body weight gain, visceral fat accumulation, hepatic steatosis, dyslipidemia, hyperglycemia, and systemic inflammation. Mechanistically, both peptides inhibited intestinal PL and CE activities and enhanced fecal lipid excretion, supporting direct suppression of intestinal fat digestion. 16S rRNA gene sequencing revealed partial restoration of HFD-disrupted gut microbiota, with APAM preferentially enriching Bifidobacterium and Roseburia, while RLPA promoted Akkermansia and Lactobacillus, accompanied by differential improvements in fecal short-chain fatty acid (SCFA) profiles. Hepatic transcriptomics identified the PPAR signaling pathway as a shared regulatory hub, and multi-omics integration revealed significant correlations linking gut microbiota, SCFA production, hepatic gene expression, and metabolic phenotypes. These findings suggest a dual-pathway anti-obesity mechanism integrating intestinal lipid digestion inhibition with gut–liver axis modulation, and highlight hemp seed protein-derived peptides as potential functional food ingredients for obesity prevention.