鞣花酸代谢产物——尿石素的研究进展

鞣花单宁和鞣花酸是广泛分布于多种蔬菜、水果和坚果中的多酚类抗氧化剂,其在胃肠道的吸收较差,生物利用率较低,但部分会被哺乳动物肠道微生物转化为更易吸收的尿石素类代谢产物。因此,人们推测这些代谢产物可能为鞣花单宁及鞣花酸发挥生物学活性的最终物质基础。本文对近年来国内外有关尿石素化学性质和抗氧化、抗炎、抗癌以及调节肠道菌群等生物活性的研究进行综述,以期为富含鞣花单宁及鞣花酸类食品的科学利用提供借鉴。     

肠道菌群对黄酮类化合物的代谢作用及生物学活性影响研究进展

黄酮类化合物是广泛存在于日常饮食中、由植物合成的次生代谢产物,具有多重生物学活性,如抗氧化、抗炎、抗癌、抗心血管疾病等。然而,黄酮类化合物的结构特点导致其在体内的生物利用度极低。近年来,研究发现黄酮类化合物能够在肠道菌群的作用下发生代谢转化,一定程度上提高了生物利用度,且其代谢产物具有与母药相似或更高的生物学活性。因此,解析黄酮类化合物在肠道菌群作用下的代谢规律及其代谢产物的生物学活性可为阐释其体内药效机理提供重要的理论参考依据。文章综述了黄酮类化合物在肠道微生物作用下的代谢反应,对黄酮类化合物经体内肠道菌群作用后代谢产物的生物学活性及机制进行相应的讨论,为明确黄酮类化合物在体内发挥生物学活性的有效形式提供理论支撑。     

微生物代谢产物影响肠道微生态系统的研究进展

肠道微生态系统是人体最重要、最复杂的微生态系统,是人体新陈代谢的重要环节之一。分子生物学、微生物组学、代谢组学的发展,高通量测序及其他检测技术的成熟,使肠道微生物及其代谢产物在机体健康、疾病中的作用机制逐渐被揭示。本文综述了微生物代谢产物对肠道微生态平衡的影响及其对机体健康的影响,并简要概括了微生物代谢产物的相关衍生应用,为代谢产物的临床干预辅助治疗应用提供参考并为生物发酵产业的发展提供科学依据。     

非淀粉多糖对肠道菌群的调节作用及其对代谢疾病影响的研究概述

膳食纤维中的非淀粉多糖（non-starch polysaccharides,NSPs）是由若干个单糖通过糖苷键连接而成的多聚体,包括纤维素、半纤维素、果胶、树胶、β-葡聚糖、果聚糖以及半乳糖等低聚糖。NSPs无法被机体消化或难以消化,因此它们几乎能完整地通过肠道,并被肠道内的微生物菌群发酵选择性地刺激肠道内微生物的增殖和活性,从而改善肠道菌群的环境。肠道微生物菌群在代谢综合征的发病机制中发挥着重要作用,通过使用益生元或益生菌来控制肠道微生物菌群,可以减少肠道低度炎症,改善肠道屏障的完整性,从而改善代谢平衡,促进减肥。因此NSPs改善肠道菌群的同时,也调节代谢疾病。该文总结NSPs与肠道菌群相互作用及改善代谢疾病的研究进展,为今后NSPs的利用提供参考。     

多酚通过肠道菌群调节能量代谢研究进展

多酚是一类植物次生代谢产物,广泛存在于人类膳食中,一般可分为3大类：酚酸类、聚合单宁类和黄酮类。多酚以及其被肠道菌群代谢的产物,能选择性调节肠道中易感微生物的生长,选择性的促进有益菌群(如乳酸菌)生长,抑制有害菌的增殖,也即引发肠道微生态的改变。这种改变对宿主产生重要影响,对宿主能量代谢的影响可能通过如下实现：1)肠道内微生物数量和种类的变化,改变微生物代谢及产酶的种类和数量;2)多酚代谢产物还可与细菌细胞表面作用,抑制酶的活性,从而影响能量代谢,减少脂肪沉积;3)多酚通过干预人体肠道菌群调整能量代谢,为预防和治疗肥胖及相关性疾病提供了新的研究思路。本文对多酚调整肠道菌群从而影响肥胖发生的作用机制进行了综述。     

膳食多酚与肠道微生物相互作用研究进展

近年来膳食多酚与肠道微生物的相互作用逐渐成为食品科学、营养学和生物学的研究热点。多酚的抗衰老、抗肿瘤、预防心脑血管疾病的功能发挥主要依赖于肠道微生物对其的代谢;多酚的肠道微生物代谢产物又会通过影响肠道微生物菌相进而影响人体健康。本文在广泛查阅文献的基础上,综述肠道微生物对膳食结合态多酚的释放、代谢和影响因素以及多酚及其代谢产物对肠道微生物菌相和酶的影响,以期为膳食多酚和肠道菌群相互作用的深入研究提供一定参考依据。     

基于肠道菌群的黄酮类化合物生理功能研究进展

黄酮类化合物是一类具有2-苯基色原酮结构的多酚化合物,广泛存在于水果、蔬菜、茶叶中,具有抗氧化、降血脂、调节血糖和抑制炎症等功效。大量研究证实黄酮类化合物在体内的代谢吸收和生理功能的发挥与肠道菌群密切相关。本文从肠道菌群的结构和功能,参与代谢的微生物种类及产物,代谢酶的种类和活性等方面阐述黄酮化合物与肠道菌群间的相互作用,总结黄酮类化合物通过调节肠道菌群预防肥胖、糖尿病、肠易激综合症、心血管疾病和阿尔兹海默症等多种疾病的机制,为黄酮类化合物在功能食品上的应用提供理论依据。     

大豆异黄酮与肠道微生物相互作用研究进展

膳食摄入大豆异黄酮与人体健康有密切的关系。大豆异黄酮糖苷组分与肠道菌群相互作用可产生生物活性和生物可利用度显著提高的新型微生物转化物,促进大豆异黄酮生理活性充分发挥。同时,大豆异黄酮通过调控肠道菌群结构影响结肠中的微生物酶活性,改变结肠菌群代谢能力。本文将对大豆异黄酮与肠道微生物的相互作用进行综述,重点阐述肠道微生物对大豆异黄酮的生物转化作用、大豆异黄酮对肠道微生物及其酶活性的调控作用以及大豆异黄酮及其肠道转化产物对健康的作用。以期为膳食组分和肠道菌群相互作用促进人体健康研究领域提供理论参考。     

膳食纤维通过调节肠道微生物及其代谢产物对动脉粥样硬化的影响研究进展

膳食纤维是一种不可被消化和吸收的碳水化合物聚合物,能够通过调节肠道微生物群的生长,促进肠道微生物区系的动态平衡,进而影响肠道微生物代谢产物如脂多糖、三甲胺N-氧化物、短链脂肪酸和胆汁酸的产生,达到调节宿主生理健康的目的。动脉粥样硬化是一种慢性炎症性疾病,其发生发展与脂质代谢紊乱和炎症反应关系密切。而肠道微生物及其代谢产物的异常已被证实是导致慢性炎症状态与脂质代谢紊乱的重要原因。近年来饮食干预动脉粥样硬化受到的关注度日益增加。本文介绍了膳食纤维的定义、膳食纤维对动脉粥样硬化的影响、膳食纤维对肠道微生物区系的影响及肠道微生物代谢产物在动脉粥样硬化中的潜在作用,以期为膳食纤维防治动脉粥样硬化提供理论参考。     

膳食主成分对肠道微生物的影响研究进展

饮食是影响肠道菌群组成和代谢的重要因素之一,更是最容易控制或改变的因素。饮食中大量营养成分的类型、数量及平衡状态会影响肠道微生物的组成和数量;同样,微生物会影响食物消化效率,并根据膳食底物产生特定的代谢产物,从而影响其他微生物及宿主健康。本文综述膳食主要成分对肠道微生物组成及代谢的影响,旨在为肠道菌群研究及其饮食调控提供一定的思路和参考。     

Ellagitannins, ellagic acid and their derived metabolites: A review about source, metabolism, functions and health

Ellagitannins (ETs) and ellagic acid (EA) are polyphenols present in some fruits, nuts and seeds, such as pomegranates, black raspberries, raspberries, strawberries, walnuts and almonds. ETs are hydrolyzed to EA under physiological conditions in vivo and EA is then gradually metabolized by the intestinal microbiota to produce different types of urolithins. Epidemiological evidence indicates that intake of ET and EA-rich foods may be protective against certain chronic diseases, although in vitro results often do not coincide with the findings of in vivo studies. This could be explained by the low bioavailability of ETs and EA antioxidant and the fact that urolithins are not as potent antioxidants as ellagitannins. On the other hand, urolithins could display estrogenic and/or anti-estrogenic activity and tissue disposition studies reveal that urolithins are enriched in prostate, intestinal, and colon tissues in mouse, which could explain why urolithins inhibit prostate and colon cancer cell growth. Moreover, antiproliferative and apoptosis-inducing activities of EA and urolithins have been demonstrated by the inhibition of cancer cell growth. The present work reviews the source, dietary intake, metabolism, functions and effects of ETs, EA and their derivate metabolites. Moreover, prebiotic, antioxidant and anti-inflammatory effects are also discussed.     

Bioactivation of Phytoestrogens: Intestinal Bacteria and Health

Phytoestrogens are polyphenols similar to human estrogens found in plants or derived from plant precursors. Phytoestrogens are found in high concentration in soya, flaxseed and other seeds, fruits, vegetables, cereals, tea, chocolate, etc. They comprise several classes of chemical compounds (stilbenes, coumestans, isoflavones, ellagitannins, and lignans) which are structurally similar to endogenous estrogens but which can have both estrogenic and antiestrogenic effects. Although epidemiological and experimental evidence indicates that intake of phytoestrogens in foods may be protective against certain chronic diseases, discrepancies have been observed between in vivo and in vitro experiments. The microbial transformations have not been reported so far in stilbenes and coumestans. However, isoflavones, ellagitanins, and lignans are metabolized by intestinal bacteria to produce equol, urolithins, and enterolignans, respectively. Equol, urolithin, and enterolignans are more bioavailable, and have more estrogenic/antiestrogenic and antioxidant activity than their precursors. Moreover, equol, urolithins and enterolignans have anti-inflammatory effects and induce antiproliferative and apoptosis-inducing activities. The transformation of isoflavones, ellagitanins, and lignans by intestinal microbiota is essential to be protective against certain chronic diseases, as cancer, cardiovascular disease, osteoporosis, and menopausal symptoms. Bioavailability, bioactivity, and health effects of dietary phytoestrogens are strongly determined by the intestinal bacteria of each individual.     

Characterization of Metabolic Pathways and Absorption of Sea Cucumber Saponins,Holothurin A and Echinoside A,in Vitro and in Vivo

Sea cucumber saponins (SCSs) exhibit a wide spectrum of bioactivities, but their metabolic characteristics are not well elucidated. In this study, the metabolism of holothurin A (HA) and echinoside A (EA), 2 major saponins in sea cucumber, by gut microflora were investigated. First, we conducted an in vitro study, where in the SCSs were incubated with intestinal microflora and the metabolites were detected by high pressure liquid chromatography–high resolution mass spectrometry. We also conducted an in vivo study on rats, where in the intestinal contents, serum, urine, and feces were collected and evaluated after oral administration of SCSs. In the in vitro study, we identified 6 deglycosylated metabolites of HA and EA, assigned M1‐M6. In the in vivo study, we found all the deglycosylated metabolites in the intestinal contents after oral administration, and both the metabolites and their prototype components could be absorbed. Four metabolites were identified in the serum, 6 in the urine, and 4 in the feces. The saponins with different structures showed different absorption characteristics in rats. According to our results, deglycosylation is the main intestinal microflora‐mediated metabolic pathway for SCSs, and both the SCSs and deglycosylated metabolites can be absorbed by intestine. This study improves the understanding of the metabolism of HA and EA by gut flora, which will be useful for further analysis of the bioactivity mechanism of SCSs.     

Metabolic Fate of Ellagitannins: Implications for Health,and Research Perspectives for Innovative Functional Foods

Consumption of dietary ellagitannins (ETs) has been associated with different health benefits. Nonetheless, ETs are not bioavailable as such and are metabolized in vivo. They are partially converted into ellagic acid (EA) in the upper gastrointestinal (GI) tract, but this first metabolite is also poorly bioavailable. In the lower GI tract, EA and residual ETs are metabolized by gut microbiota to produce urolithins, which, together with their conjugate relatives, persist at relatively high concentrations in plasma and urine for days after ingestion of dietary ETs. Thus, ETs and EA may exert local health benefits on the GI tract but systemic health benefits are more likely to result from urolithins. Cellular models suggest that, at physiological concentration, urolithins are active against chronic degenerative diseases. Health benefits have been proven in animal models and during clinical studies. Even so, the crucial involvement of gut microbiota in ET bioconversion induces important variability of physiological response among humans, giving rise to the concept of high and low urolithin producers. This variability among consumers in obtaining potential health benefits from dietary ETs raises new challenges for the functional food industry. Different research perspectives are discussed to tackle this significant issue for nutritionists, food technologists, and consumers.     

亚麻籽胶结构及功能应用研究进展

亚麻籽胶是一种阴离子杂多糖,主要存在于亚麻籽外种皮最外层,含量占亚麻籽重量9%左右。作为一种亲水性胶体,亚麻籽胶具有黏稠性、乳化性、胶凝性、抗氧化等特性,能够作为一种食品添加剂与食品体系中其它组分产生交互作用协同提高食品加工特性。此外,作为一种水溶性膳食纤维,亚麻籽胶还具有降血糖、降血脂、调节肠道菌群和减肥等作用。该文主要探究亚麻籽胶精细结构、功能特性、生物活性和应用等方面最新研究进展,以期为亚麻籽胶高值化加工和利用提供参考。     

肠道菌群与特殊环境关系的研究进展

肠道菌群的动态平衡是维持人体健康的重要标志之一,许多疾病证实与肠道菌群失调有关。环境是影响肠道菌群的重要因素,进一步可分为常规环境和特殊环境,其中关于特殊环境与肠道菌群之间相互联系的研究少之又少,而两者之间的相互作用对在特殊环境下工作的特殊人群健康具有十分重要的意义。因此,本文从特殊环境入手,重点探讨高原、航空航天、航海等几类特殊环境下人体肠道菌群的变化以及通过饮食干预调节肠道菌群,以期为适应特殊环境,改善特殊人群健康提供参考。     

植物多酚抗肥胖作用的研究进展

植物多酚是一类广泛存在于植物体内的次生代谢产物,具有抗癌、抗氧化、抗菌、抗病毒等生物活性。随着肥胖发生率的急速增加,抗肥胖药物或功能性食品的研究成为了热点。植物多酚类化合物抗肥胖效果显著,近年来其抗肥胖机理也得到了进一步的阐明,本文对植物多酚在调节代谢酶活性、刺激机体产热、调节机体信号和肠道微生物菌群方面的抗肥胖研究进展进行综述。     

Digestion property and synergistic effect on biological activity of purple rice (Oryza sativa L.) anthocyanins subjected to a simulated gastrointestinal digestion in vitro

Anthocyanins, a group of polyphenolic pigments, have been proved to possess various bioactivities. However, they are unstable in the small intestine and absorbed with low bioavailability. The discrepancy between the low bioavailability of anthocyanins and their good bioactivities has not been illuminated yet. Moreover, information about the digested property and stability of purple rice anthocyanins in the alimentary tract is still limited. Thus, the present work was designed to study the digestion property and the changes in antioxidant and cytoprotective activities of purple rice anthocyanins using an in vitro digestion model, and to investigate the interactions between gastric and intestinal digested anthocyanins. The results showed that anthocyanins amount and antioxidant and cytoprotective effects didn't change significantly during gastric digestion. However, about 76% of total anthocyanins were degraded during intestinal digestion. The IC₅₀ values of intestinal digested sample tested by DPPH and ABTS methods were about 19.1 and 16.9 μg/mL, respectively, far higher than that of non-digested sample (about 7.7 and 7.1 μg/mL, respectively). Cytoprotective effect of intestinal digested sample also decreased significantly. Synergistic effects on antioxidant and cytoprotective activities were observed between the gastric and intestinal digested samples at a relative low concentration. Those results suggest that the bioactivities of purple rice anthocyanins may be changed after digestion and enhanced through the synergies between their gastric and intestinal digested catabolites.     

海藻多糖与肠道菌群相互作用研究进展

肠道菌群是寄居于宿主体内的共生微生物群体, 在维持机体健康及控制疾病发生等方面发挥着重要作用。海藻多糖是从海藻中提取出的一种具有生物活性的膳食纤维, 具有抗肿瘤、抗氧化、抗病毒、降血糖、免疫调节等多种活性。研究发现海藻多糖不能被人体消化酶降解, 但可以被肠道菌群降解和利用, 而海藻多糖又可以通过调节肠道菌群影响机体健康。本文综述了肠道菌群对海藻多糖的降解利用, 海藻多糖通过调节肠道菌群改善炎症性肠病、高血脂、糖尿病等疾病, 探讨了海藻多糖结构对肠道菌群的影响, 以期为海藻多糖与肠道菌群相互作用在改善人体健康方面的研究提供一定参考。     

红枣多糖提取、分离纯化及生物活性研究进展

红枣作为我国传统的药食同源的天然保健果品,已有近四千多年的栽植和食用历史。红枣多糖是一种复合杂多糖,现代药理学研究表明多糖是红枣果中主要的功能活性成分之一,具有抗氧化、抗肿瘤、免疫保肝及调节肠道菌群等功能。本文系统地综述了国内外近年来关于红枣多糖提取、分离纯化、结构特征及生物活性的研究进展,以期为提高红枣多糖的利用以及为进一步深入研究红枣多糖构效关系提供理论依据。