Unveiling the Antiobesity Mechanism of Sweet Potato Extract

Professor Huang Dejian, Chief Principal Investigator from the Biomedical and Health Technology Research Platform of NUSRI Suzhou, and his team member Associate Investigator Liu Tiange havepublished their results in the Journal of Agricultural and Food Chemistry (JAFC). Featured as the cover article of the April 2024 issue, the study employed a high-fat diet (HFD)-induced mouse model of obesity and integrated analytical chemistry, hepatic transcriptomics, metabolomics, and gut microbiome profiling to elucidate the regulatory mechanisms of sweet potato extract (SPE) on lipid metabolism. The team also characterized the bioavailability of its key bioactive components resin glycosides in vivo. Their findings not only offer novel strategies for obesity management but also lay a solid theoretical foundation for the selective breeding of functional sweet potato cultivars and the valorization of sweet potato byproducts.

Background

With over 2.5 billion individuals worldwide affected by overweight and obesity, developing safe and effective natural interventions has become a key focus of the scientific community. To address this challenge, Professor Dejian Huang’s team investigated  sweet potato (Ipomoea batatas L.), the world’s sixth most important staple crop, and discovered that SPE effectively controlled weight gain in mice, although its underlying mechanisms remained unclear.

Results

In HFD-induced obese mice, oral administration  of SPE yielded significant therapeutic outcomes:: reduced body weight gain, lowered serum LDL cholesterol levels, decreased hepatic lipid accumulation, and  inhibited white adipocyte hypertrophy. These beneficial  effects were strongly associated with  gut microbiota remodelling.

Notably, SPE significantly increased the relative abundance of the key genus Eubacterium_coprostanoligenes_group_unclassified in the mouse colon, while reducing the level of the genus Kineothrix. These microbial alterations were associated with elevated levels of short-chain fatty acids. Integrative analyses of liver transcriptome and metabolome, along with Spearman correlation, revealed that SPE may exert antiobesity effects by modulating the bile-sphingolipid metabolism via the gut–liver axis.

Also, SPE enhanced dietary fat excretion, a finding supported by its in vitro inhibition of pancreatic lipase activity by resin glycosides. LC-QTOF-MS analysis showed reduced fecal levels of multiple resin glycoside compounds, indicating their partial utilization in vivo and possible role as key active compounds contributing to weight loss. These results offer mechanistic insights into SPE’s impact on lipid metabolism and support its potential as a functional food ingredient.

Application

This study provides compelling evidence for SPE as a promising natural antiobesity agent. It holds great potential for future application in precision nutrition strategies aimed at managing obesity and metabolic disorders.