Abstract:
(1) Background: Recently, academic studies are demonstrating that the cholesterol-lowering effects of pectin oligosaccharides (POSs) are correlated to intestinal flora. However, the mechanisms of POS on cholesterol metabolisms are limited, and the observations of intestinal flora are lacking integrative analyses. (2) Aim and methods: To reveal the regulatory mechanisms of POS on cholesterol metabolism via an integrative analysis of the gut microbiota, the changes in gut microbiota structure and metabolite composition after POS addition were investigated using Illumina MiSeq sequencing and non-targeted metabolomics through in vitro gut microbiota fermentation. (3) Results: The composition of fecal gut flora was adjusted positively by POS. POS increased the abundances of the cholesterol-related bacterial groups Bacteroidetes, Bifidobacterium and Lactobacillus, while it decreased conditional pathogenic Escherichia coli and Enterococcus, showing good prebiotic activities. POS changed the composition of gut microbiota fermentation metabolites (P24), causing significant changes in 221 species of fermentation metabolites in a non-targeted metabolomics analysis and promoting the production of short-chain fatty acids. The abundances of four types of cholesterol metabolism-related metabolites (adenosine monophosphate, cyclic adenosine monophosphate, guanosine and butyrate) were significantly higher in the P24 group than those in the control group without POS addition. (4) Conclusion: The abovementioned results may explain the hypocholesterolemic effects of POS and promotion effects on cholesterol efflux of P24. These findings indicated that the potential regulatory mechanisms of citrus POS on cholesterol metabolism are modulated by cholesterol-related gut microbiota and specific metabolites.
摘要:
(1)背景:最近,学术研究表明,果胶寡糖(POSs)的降胆固醇作用与肠道菌群相关。然而,POS对胆固醇代谢的机制是有限的,肠道菌群的观察缺乏综合分析。(2)目的和方法:通过对肠道菌群的综合分析,揭示POS对胆固醇代谢的调控机制。通过体外肠道菌群发酵,使用IlluminaMiSeq测序和非靶向代谢组学研究了添加POS后肠道菌群结构和代谢物组成的变化.(3)结果:POS对粪便肠道菌群的组成有积极的调节作用。POS增加了胆固醇相关细菌群的丰度拟杆菌,双歧杆菌和乳杆菌,虽然它减少了条件致病性大肠杆菌和肠球菌,表现出良好的益生元活性。POS改变了肠道菌群发酵代谢产物的组成(P24),在非靶向代谢组学分析中引起221种发酵代谢物的显著变化,并促进短链脂肪酸的产生。四种类型的胆固醇代谢相关代谢物的丰度(腺苷一磷酸,环磷酸腺苷,P24组的鸟苷和丁酸酯)明显高于未添加POS的对照组。(4)结论:上述结果可能解释了POS的低胆固醇血症作用和P24对胆固醇流出的促进作用。这些发现表明,柑橘POS对胆固醇代谢的潜在调节机制受到胆固醇相关肠道菌群和特定代谢产物的调节。