Tecnológico Nacional de México/Instituto Tecnológico de Tepic, Av. Tecnológico No 2595, Col. Lagos del Country CP, 63175 Tepic, Nayarit, Mexico.
Tecnológico Nacional de México/Instituto Tecnológico de Tepic, Av. Tecnológico No 2595, Col. Lagos del Country CP, 63175 Tepic, Nayarit, Mexico.
Food Res Int. 2020 Jun;132:109036. doi: 10.1016/j.foodres.2020.109036. Epub 2020 Jan 30.
Hibiscus sabdariffa (Hb) calyces are a source of dietary fiber (DF) and phenolic compounds. Agave fructans (AF) and oligofructans (OF) are considered as soluble DF. The aim of the study was to investigate changes in gut microbiota upon feeding predigested Hb, AF, OF or Mix (Hb/AF) to a dynamic, validated in vitro model of the human colon (TIM-2), using sequencing of the V3-V4 regions of the 16S rRNA gene. A pooled human fecal microbiota was used. Production of short-chain fatty acids (SCFAs), branched-chain fatty acids (BSCFAs) and ammonia was also assessed. Samples were taken after 0, 24, 48 and 72 h. Principal component (PC) analysis of fermentation metabolites and relative abundance of genera was carried out, and extracted factors were based on eigenvalues >1.0 and explained >60% of variance. Fermentation of samples resulted in different SCFAS concentrations. The highest butyric acid production was on AF and OF, while the molar ratio of SCFAS on Hb was 63:18:18 for acetic, propionic and butyric acid, respectively. BSCFAS were also produced upon feeding the studied substrates, but in much lower concentrations. About 45 bacteria genera were identified and 10 of these were the most abundant changing during the fermentation time, amongst which a high relative abundance in Bifidobacterium, Bacteroides and Catenibacterium, that changed during the fermentation time depending of substrate. Hb feeding after 48 h led to Bifidobacterium being the most abundant genus. Two PCs were identified: after 24 h of fermentation PC1 was highly influenced by Bifidobacterium and Prevotella, which was related with Hb and SIEM feeding. Evaluation of the changes in metabolites and gut microbiota composition during colonic fermentation in a validated in vitro model provides a complete and reliable view of the potential prebiotic effect of different dietary fibers.
玫瑰茄（Hb）花萼是膳食纤维（DF）和酚类化合物的来源。龙舌兰果糖（AF）和低聚果糖（OF）被认为是可溶性 DF。本研究的目的是使用经过验证的体外人类结肠模型（TIM-2），通过测序 16S rRNA 基因的 V3-V4 区，研究喂食消化后的 Hb、AF、OF 或混合（Hb/AF）对肠道微生物群的变化。使用了混合的人类粪便微生物群。还评估了短链脂肪酸（SCFA）、支链脂肪酸（BSCFA）和氨的产生。在 0、24、48 和 72 小时后取样。对发酵代谢物和属的相对丰度进行主成分（PC）分析，并基于特征值>1.0 和解释方差>60%提取因子。样品的发酵导致不同的 SCFA 浓度。AF 和 OF 产生的丁酸产量最高，而 Hb 的 SCFA 摩尔比分别为乙酸、丙酸和丁酸的 63:18:18。喂养研究底物也产生了 BSCFA，但浓度要低得多。鉴定出约 45 个细菌属，其中 10 个是在发酵过程中变化最大的丰富属，其中双歧杆菌、拟杆菌和双歧杆菌的相对丰度较高，这些属在发酵过程中随底物而变化。48 小时后喂食 Hb 导致双歧杆菌成为最丰富的属。确定了两个 PC：发酵 24 小时后，PC1 受双歧杆菌和普雷沃氏菌的高度影响，这与 Hb 和 SIEM 的喂养有关。在验证的体外模型中评估结肠发酵过程中代谢物和肠道微生物群组成的变化，为不同膳食纤维的潜在益生元效应提供了全面可靠的观点。
