Walnut‐derived peptides combined with intermittent fasting alleviated obesity by modulating gut microbiota and liver metabolome in high‐fat‐diet‐induced obesity mice

BACKGROUND: This study aimed to investigate the anti-obesity mechanism of walnut-derived peptides (WMP) combined with intermittent fasting (IF) through modulating the gut microbiota-liver metabolism axis in high-fat-diet (HFD)-induced obese mice, providing theoretical support for dietary intervention strategies. METHODS: Fifty C57BL/6 mice were divided into five groups (n = 10): normal diet, HFD, WMP, IF and WMP + IF, with an 8-week intervention. Biochemical analysis, 16S rRNA sequencing, and untargeted liver metabolomics were employed to explore the underlying mechanisms. RESULTS: WMP + IF significantly alleviated hyperlipidemia, glucose metabolism disorders, insulin resistance, and visceral fat deposition in HFD mice, while suppressing systemic inflammation. Gut microbiota analysis revealed reduced abundance of Firmicutes, Kineothrix, and Dubosiella, along with a decreased Firmicutes/Bacteroidota (F/B) ratio, whereas Bacteroidota and CAG-873 were enriched. Correlation analysis demonstrated positive associations between Firmicutes and obesity-related markers (lipid profiles, liver dysfunction, pro-inflammatory cytokines), while Bacteroidota exhibited negative correlations. Untargeted metabolomics identified upregulated levels of 16-hydroxypalmitic acid and 13-S-hydroxyoctadecadienoic acid (13(S)-HODE), alongside activation of ABC transporters and galactose metabolism pathways. Notably, 13(S)-HODE showed negative correlations with Firmicutes, F/B ratio, and Kineothrix, but positive correlations with Bacteroidota and CAG-873. CONCLUSION: The synergistic anti-obesity effects of WMP and IF are mediated through restoring gut microbial balance and reprogramming hepatic metabolic pathways. These findings highlight novel mechanisms involving the gut-liver axis, offering innovative strategies for obesity prevention through natural bioactive compounds combined with dietary interventions. © 2025 Society of Chemical Industry.