Comparison of three methods of intermittent fasting in high-fat-diet-induced obese mice

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.

Chronic intermittent fasting impairs β cell maturation and function in adolescent mice

Intermittent fasting (IF) is a nutritional lifestyle intervention with broad metabolic benefits, but whether the impact of IF depends on the individual's age is unclear. Here, we investigated the effects of IF on systemic metabolism and β cell function in old, middle-aged, and young mice. Short-term IF improves glucose homeostasis across all age groups without altering islet function and morphology. In contrast, while chronic IF is beneficial for adult mice, it results in impaired β cell function in the young. Using single-cell RNA sequencing (scRNA-seq), we delineate that the β cell maturation and function scores are reduced in young mice. In human islets, a similar pattern is observed in type 1 (T1D), but not type 2 (T2D), diabetes, suggesting that the impact of chronic IF in adolescence is linked to the development of β cell dysfunction. Our study suggests considering the duration of IF in younger persons, as it may worsen rather than reduce diabetes outcomes.

The effect of intermittent fasting on microbiota as a therapeutic approach in obesity

Obesity, a public health challenge, arises from a complex interplay of factors such as dietary habits and genetic predisposition. Alterations in gut microbiota, characterized by an imbalance between Firmicutes and Bacteroidetes, further exacerbate metabolic dysregulation, promoting inflammation and metabolic disturbances. Intermittent fasting (IF) emerges as a promising dietary strategy showing efficacy in weight management and favoring fat utilization. Studies have used mice as animal models to demonstrate the impact of IF on gut microbiota composition, highlighting enhanced metabolism and reduced inflammation. In humans, preliminary evidence suggests that IF promotes a healthy microbiota profile, with increased richness and abundance of beneficial bacterial strains like Lactobacillus and Akkermansia. However, further clinical trials are necessary to validate these findings and elucidate the long-term effects of IF on microbiota and obesity. Future research should focus on specific tissues and cells, the use of advanced -omics techniques, and exploring the interaction of IF with other dietary patterns, to analyze microbiota composition, gene expression, and potential synergistic effects for enhanced metabolic health. While preliminary evidence supports the potential benefits of IF in obesity management and microbiota regulation, further research with diverse populations and robust methodologies is necessary to understand its implications and optimize personalized dietary interventions. This review explores the potential impact of IF on gut microbiota and its intricate relationship with obesity. Specifically, we will focus on elucidating the underlying mechanisms through which IF affects microbiota composition, as well as its subsequent effects on obesity.