Polygonatum kingianum Coll. et Hemsl enzymatic saccharifying extracts alleviate HFD-induced obesity in mice via regulating gut microbiota and AMPK pathways

Polygonatum is a traditional Chinese food with a long history of consumption. The effects of Polygonatum kingianum Coll. et Hemsl on hyperlipidemia have been partially reported, but the specific mechanisms involved in improving long-term high-fat diet-induced obesity remain unclear. This study investigated the effects of Polygonatum kingianum Coll. et Hemsl enzymatic saccharifying extract (ESP) on hepatic lipid metabolism, the gut microbiota, and short-chain fatty acid axis homeostasis in a long-term HFD-induced obesity animal model and explored the possible underlying mechanisms. The experimental results unequivocally demonstrated that ESP has a positive effect on reducing weight gain and decreasing fat deposition. Additionally, ESP ameliorates lipid metabolism disorders, mitigates liver fat degeneration, counters insulin resistance, and alleviates mild inflammation. Furthermore, ESP suppresses the secretion of hormones such as leptin, ghrelin, and neuropeptide Y. The activation of the AMP-activated protein kinase (AMPK) signaling pathway augments energy expenditure and diminishes lipid production. Moreover, ESP reduces the abundance of bacteria positively correlated with obesity, such as Desulfovibrio, Acinetobacter, and Dubosiella; promotes the proliferation of beneficial bacteria inversely associated with obesity, such as Bifidobacterium, Akkermansia, and Lactobacillus; and elevates the levels of short-chain fatty acids (SCFAs). It is plausible that the potential mechanism of ESP action involves the regulation of the AMPK signaling pathway in the liver through the microbiota-SCFA-liver axis, consequently alleviating obesity induced by a high-fat diet. ESP, an innovative food product with medicinal properties, holds substantial promise and potential for obesity prevention and treatment.