Effect of 1-Kestose on Lipid Metabolism in a High-Fat-Diet Rat Model

<b>Objectives:</b> Hyperlipidemia is a risk factor for various diseases. Identifying food components that can help reduce the levels of blood lipids, such as cholesterol and triglycerides, is a global research priority. It has been reported that 1-Kestose, a fructooligosaccharide, can reduce blood cholesterol and triglyceride levels in rats; however, the underlying mechanisms remain unclear. Therefore, we aimed to elucidate the effects of 1-kestose supplementation on lipid metabolism and the gut environment in rats. <b>Methods</b>: Twenty male Sprague-Dawley rats (age 8 weeks) were provided 1-kestose-containing water and were maintained for two weeks. After dissection, the blood components, hepatic gene expression, gut microbiota, and bile acid composition in the cecal contents of the rats were analyzed. <b>Results</b>: The 1-Kestose intake reduced plasma cholesterol and triglyceride levels. Additionally, an increase in cytochrome P450 family 7 subfamily A member 1 mRNA expression, a key gene for bile acid synthesis in the liver, and a decrease in lipid synthesis-related mRNA expression were observed. In the cecum, the levels of deconjugated bile acids, which are involved in the regulation of lipid synthesis, were increased. Furthermore, the 1-kestose intake altered the gut microbiota in the cecum, leading to an increase in the abundance of specific bacteria, such as <i>Bifidobacterium</i>, which are involved in the deconjugation of conjugated bile acids. <b>Conclusions</b>: The intake of 1-kestose alters the gut microbiota and bile acid metabolism in the cecum, potentially influencing lipid metabolism in the host.