Baumgartner Sabine, Mensink Ronald P, Smet Els De, Konings Maurice, Fuentes Susana, de Vos Willem M, Plat Jogchum
Department of Human Biology and Movement Sciences, Maastricht University Medical Center+, 6229 ER Maastricht, the Netherlands.
Department of Human Biology and Movement Sciences, Maastricht University Medical Center+, 6229 ER Maastricht, the Netherlands.
J Steroid Biochem Mol Biol. 2017 May;169:46-53. doi: 10.1016/j.jsbmb.2016.02.029. Epub 2016 Mar 3.
Information regarding dietary effects on plasma oxyphytosterol concentrations as well as on the origin of oxyphytosterols is scarce. We hypothesized that plant sterols are oxidized in the intestinal lumen, mediated by microbial activity, followed by uptake into the circulation. To address this hypothesis, we carried out, a randomized, double blind, crossover study in 13 healthy subjects, who consumed for 3 weeks control and plant stanol ester enriched margarines (3.0g/d plant stanols) separated by a 4-week wash-out period. Plasma oxy(phyto)sterols were determined via GC-MS/MS, while microbiota analyses were performed on fecal DNA using a phylogenetic microarray to assess microbial composition and diversity. Plasma plant sterol concentrations did not correlate with plasma oxyphytosterols concentrations at baseline. Plant stanol consumption reduced serum sitosterol and campesterol concentrations (-37% and -38%), respectively (p<0.001), as well as plasma concentrations of 7β-OH-campesterol (-24%; p<0.05), 7β-OH-sitosterol (-17%; p<0.05) and 7-keto-sitosterol (-13%; p<0.05). Although the intestinal microbiota composition and diversity of the faecal contents were not different between the two periods, we observed significant correlations between several specific bacterial groups and plasma plant sterol, but not with plasma oxyphytosterol concentrations. In conclusion, plant stanol ester consumption reduced serum plant sterol and plasma oxyphytosterol concentrations, while intestinal microbiota composition and diversity were not changed. To definitely answer the effects of microbiota on oxyphytosterol formation, future studies could examine oxyphytosterol concentrations after changing intestinal microbial composition or by measuring intestinal oxyphytosterol formation after providing labelled non-oxidized plant sterols.
关于饮食对血浆氧化植物甾醇浓度以及氧化植物甾醇来源的影响的信息很少。我们推测植物甾醇在肠腔内被微生物活动介导氧化，随后被吸收进入循环系统。为了验证这一假设，我们对13名健康受试者进行了一项随机、双盲、交叉研究，受试者分别食用3周的对照人造黄油和富含植物甾烷醇酯的人造黄油（每天3.0克植物甾烷醇），中间间隔4周的洗脱期。通过气相色谱-串联质谱法测定血浆氧化（植物）甾醇，同时使用系统发育微阵列对粪便DNA进行微生物群分析，以评估微生物组成和多样性。在基线时，血浆植物甾醇浓度与血浆氧化植物甾醇浓度不相关。食用植物甾烷醇可分别降低血清谷甾醇和菜油甾醇浓度（分别降低37%和38%）（p<0.001），以及7β-羟基菜油甾醇（降低24%；p<0.05）、7β-羟基谷甾醇（降低17%；p<0.05）和7-酮基谷甾醇（降低13%；p<0.05）的血浆浓度。尽管两个时期粪便内容物的肠道微生物群组成和多样性没有差异，但我们观察到几个特定细菌群与血浆植物甾醇之间存在显著相关性，但与血浆氧化植物甾醇浓度无关。总之，食用植物甾烷醇酯可降低血清植物甾醇和血浆氧化植物甾醇浓度，而肠道微生物群组成和多样性未发生变化。为了明确回答微生物群对氧化植物甾醇形成的影响，未来的研究可以在改变肠道微生物组成后检测氧化植物甾醇浓度，或者在提供标记的未氧化植物甾醇后测量肠道氧化植物甾醇的形成。
