银杏组织培养生产黄酮、内酯的研究

该文从品种、外植体类型、培养方式、外源添加物、诱导发根等方面对近几年来组织培养生产银杏内酯和黄酮类化合物取得的进展进行了系统。     

青钱柳黄酮及三萜调节人体肠道菌群作用研究

以青钱柳为材料,通过热水浸提,大孔树脂柱层析分离纯化,制备得到纯度大于90%的青钱柳黄酮和三萜。继而采用体外厌氧粪样混合培养与荧光原位杂交技术,评价青钱柳黄酮和三萜对于人体肠道菌群的调节作用。结果表明青钱柳黄酮和三萜类物质能有效促进肠道中有益细菌(双歧杆菌和乳酸菌)的增殖,而对于梭状菌和拟杆菌则有抑制作用,同时未显著影响肠道总菌群的数量。研究表明,青钱柳中的黄酮和三萜类物质,对于改善人体肠道环境、维护人体健康具有重要作用。     

银杏植物各部位及银杏组织培养细胞中银杏内酯B和白果内酯含量的初步研究

用高压液相色谱法对五年生扦插银杏各部位及银杏组织培养细胞中银杏内酯B和白果内酯的含量进行了测定.结果表明银杏内酯B和白果内酯在银杏植物各部位的含量差异很大.银杏内酯B在银杏叶中含量最高,白果内酯在银杏侧根中含量最高.在6,7-v培养基下银杏组织培养细胞中同时测出银杏内酯B和白果内酯,提示用植物组织培养方法有可能同时产生银杏内酯B和白果内酯.     

肠道菌群与人体代谢

人体代谢是人为了适应环境变化通过自身与微生物基因组共调节产生的所有复杂化学反应的总称。无论疾病与否,规模宏大而复杂的细菌库——肠道菌群都直接参与人体多种代谢过程。肠道菌群在人体内形成了错综复杂的微生态系统,与人类共同变化应对外界因素,人体代谢平衡状况与肠道菌群的结构组成变化密不可分。研究肠道菌群与人体代谢的相关性,对于人类健康有重要意义。     

银杏叶中银杏内酯B及白果内酯的分离鉴定

前文中作者已报道从我国特有植物银杏(Ginkgo biloba L.)的叶子中分到银杏内酯A及C(ginkgolide A,C),本文报道从银杏叶中分到的另外二个结晶,经理化性质、薄层层析、红外光谱及质谱分析,鉴定结晶Ⅲ为银杏内酯B(ginkgolide B),结晶Ⅳ为白果内酯(bilobalide),后者为国内首次分离。     

硫酸锌对人体肠道菌群的体外影响

研究硫酸锌对人体肠道菌群结构及代谢产物的体外影响,为锌盐的临床应用提供肠道菌群方面的理论依据。借助体外发酵、宏基因组测序及气相色谱技术研究硫酸锌对肠道菌群及短链脂肪酸的影响。结果发现,硫酸锌显著提高克雷伯氏菌属（Klebsiella）、欧文氏菌属（Erwinia）、慢生根瘤菌属（Bradyrhizobium）、丙酸杆菌属（Propionibacterium）、担子菌门（Basidiomycota）和拉恩氏菌属（Rahnella）等的相对丰度,显著降低巨单胞菌属（Megamonas）、新月形单胞菌科（Selenomonadaceae）和厚壁菌纲（Negativicutes）等的相对丰度。种水平上硫酸锌显著提高肺炎克雷伯氏菌（Klebsiella pneumonia）、长双歧杆菌（Bifidobacterium longum）、Scandinavium goeteborgense、类肺炎克雷伯氏菌（Klebsiella quasipneumoniae）、产气克雷伯菌（Klebsiella aerogenes）、马氏棒杆菌（Corynebacterium matruchotii）、人葡萄球菌...     

银杏黄酮苷和萜类内酯含量的季节变化

以银杏（Ginkgo biloba L.)2年生实生苗和大树为试材,分析根、茎和叶中银杏黄酮苷及萜类内酯含量的季节变化规律。银杏叶中萜类内酯含量从春季起逐渐增加,至夏末秋初达最高值,随后逐渐减少;根和茎中萜类内酯含量的季节变化与叶中相类似,但在冬季休眠期维持较高含量,进入春季伴随叶的萌发生长降低到全年的最低点。银杏茎中萜类内酯含量最低,相当于叶含量的1／3和根含量的1／2。叶中白果内酯含量在总萜类内酯中所占比例较高,而在根和茎中所占比例则较低。随着树龄增加,银杏叶萜类内酯含量下降,这可能与萜类内酯合成能力下降有关。银杏黄酮苷含量在春季幼叶中最高,夏季和秋季相对较低且变化不明显;长枝叶中槲皮素较多,而短枝叶中山柰黄素较多。对不同季节和不同部位的不同成分含量的相关机理进行了讨论。     

银杏外种皮的双黄酮成分

从银杏外种皮的乙酸乙酯提取中分离得到６个化合物,其中５个经物理常数及光谱分析鉴定为金松双黄酮、银杏素、奶杏素、１－５’－甲氧基白果素及白果素。这些化合物均首次从银杏外种皮分离。     

光强与光质对银杏光合作用及黄酮苷与萜类内酯含量的影响

对2年生银杏（Ginkgo biloba L.)苗进行遮荫和光膜处理,测定光合速率及碳水化合物,银杏黄酮苷与萜类内酯的含量。光合速率在自然光下测定时从大到小依次为：黄膜＞蓝膜和红膜＞绿膜＞紫膜和白膜,在光膜下测定时为：黄膜＞红膜＞蓝膜、紫膜和白膜＞绿膜。光强和光质对碳水化合物含量有显著影响。光质对萜类内酯的生物合成和积累有影响,紫膜处理的银杏萜类内酯含量最高,为3.89mg/g,比白膜（对照） 高85．23％,其次是绿膜,为2．80mg/g。覆膜和蔗荫显著减少银杏黄酮苷含量,这可能与紫外辐射强度减弱有关。     

(S)-雌马酚对肠道菌群的体外调控作用及其可代谢性研究

[目的]研究(S)-雌马酚对人体肠道菌群的体外调控作用和人体肠道菌群对(S)-雌马酚的代谢衍生作用。[方法]采用人体肠道菌群体外批量发酵、细菌16S rRNA基因高通量测序、气相色谱、液相色谱和质谱等检测(S)-雌马酚与人体肠道菌群体外相互作用。[结果]体外添加(S)-雌马酚对总体人肠道菌群结构和短链脂肪酸产量影响不明显。添加0.45 mmol/L (S)-雌马酚组与对照组相比,未检测到相对丰度发生显著变化的细菌;添加0.90 mmol/L (S)-雌马酚组与对照组相比,显著增加了肠杆菌科(Enterobacteriaceae)等条件致病菌的相对丰度,减少了潜在益生菌粪球菌属(Coprococcus)的比例。代谢分析发现,发酵培养液中(S)-雌马酚的浓度降低了约15%−30%,推测可能被微生物进一步降解或衍生修饰。[结论]从体外调控肠道菌群的角度判断,0.45 mmol/L (S)-雌马酚相对较安全,而0.90 mmol/L (S)-雌马酚可能会破坏肠道菌群平衡。(S)-雌马酚可以被人体肠道菌群进一步代谢,其特定代谢产物的结构与功能及其体内生物安全性有待进一步研究。     

Proteomics,human gut microbiota and probiotics

The various bacterial communities associated with humans have many functions and the gut microbiota has a major role in the host. Bacterial imbalance in the gut, known as dysbiosis, has therefore been linked to several diseases. Probiotics, that is, microbial strains that have beneficial effects on the host, are thought to benefit this intestinal ecosystem. Hence, knowledge of the gut microbiota composition and an understanding of its functionalities are of interest. Recently, efforts have focused on developing new high-throughput techniques for studying microbial cells and complex communities. Among them, proteomics is increasingly being used. The purpose of this article is to focus on the recent development of this technology and its usefulness in analyzing the human gut ecosystem and probiotic strains.     

肠道微生物与线粒体之间的互作

肠道微生物与肠道细胞线粒体功能之间的关系十分密切。一方面,肠道微生物可直接或通过短链脂肪酸、硫化氢和一氧化氮等代谢产物间接影响与线粒体相关的能量代谢过程,调节线粒体活性氧的产生,调控线粒体甚至整个机体的免疫反应。另一方面,肠道细胞线粒体功能紊乱和基因组的遗传变异也会影响肠道微生物的组成和功能。本文主要介绍了肠道微生物和线粒体之间的互作关系的最新研究进展,为靶向作用于肠道菌群和线粒体以调节肠道健康提供理论依据。     

慢性乙型肝炎患者肠道菌群与肝脏生化指标的相关性

乙型肝炎病毒感染引起的慢性乙型肝炎(Chronic hepatitis B,CHB)是一种全球性流行疾病,严重时可引起肝功能衰竭,甚至发展成肝硬化和肝癌.也已发现CHB的发生和发展与肠道菌群的组成和结构的变化密切相关.为进一步探究肠道菌群结构与肝脏生化指标之间的联系,文中随机纳入14名CHB患者和11名健康对照者(Co...     

A review on the interactions between gut microbiota and innate immunity of fish

Although fish immunology has progressed in the last few years, the contribution of the normal endogenous microbiota to the overall health status has been so far underestimated. In this context, the establishment of a normal or protective microbiota constitutes a key component to maintain good health, through competitive exclusion mechanisms, and has implications for the development and maturation of the immune system. The normal microbiota influences the innate immune system, which is of vital importance for the disease resistance of fish and is divided into physical barriers, humoral and cellular components. Innate humoral parameters include antimicrobial peptides, lysozyme, complement components, transferrin, pentraxins, lectins, antiproteases and natural antibodies, whereas nonspecific cytotoxic cells and phagocytes (monocytes/macrophages and neutrophils) constitute innate cellular immune effectors. Cytokines are an integral component of the adaptive and innate immune response, particularly IL-1 beta, interferon, tumor necrosis factor-alpha, transforming growth factor-beta and several chemokines regulate innate immunity. This review covers the innate immune mechanisms of protection against pathogens, in relation with the installation and composition of the normal endogenous microbiota in fish and its role on health. Knowledge of such interaction may offer novel and useful means designing adequate therapeutic strategies for disease prevention and treatment.     

肠道微生物与昆虫的共生关系

昆虫肠道栖息着大量的微生物。随着近年来研究肠道微生物的方法不断进步,尤其是基于16S rDNA的分子生物学方法的应用,人们对肠道微生物的了解逐渐加深。昆虫肠道对于微生物的拓殖存在一定的选择作用。肠道微生物对昆虫寄主的作用包括提供营养、利用拓殖抗性抵抗外来微生物侵袭、参与多重营养关系、引起昆虫免疫反应。长期进化过程中肠道微生物与昆虫发展出紧密的共生关系,微生物发展出一系列手段适应昆虫肠道环境。文章从以上几个方面对近年来的研究进展进行总结,并对昆虫肠道微生态学的实践意义和将来可能的研究热点进行展望。     

Interactive relationship between Trp metabolites and gut microbiota: The impact on human pathology of disease

Tryptophan (Trp), an α-amino acid, is the precursor of serotonin (5-hydroxytryptamine, 5-HT), which is involved in a variety of features of metabolic function and human nutrition. Evidence highlights the role of Trp metabolites (exclusively 5-HT) in the gastrointestinal (GI) tract; however, the mechanisms of action involved in the release of 5-HT in the GI tract are still unknown. Considering the fact that variations of 5-HT may facilitate the growth of certain GI disorders, gaining a better understanding of the function and release of 5-HT in the GI tract would be beneficial. Additionally, investigating Trp metabolism may clarify the relationship between Trp and gut microbiota. It is believed that other metabolites of Trp (mostly that of the kynurenine pathway) may play a significant role in controlling gut microbiota function. In this review, we have attempted to summarize the current research investigating the relationship of gut microbiota, Trp and 5-HT metabolism (with particular attention paid to their metabolite type, as well as a discussion of the research methods used in each study). Taking together, regarding the role that Trp/5-HT plays in a range of physical and mental diseases, the gut bacterial types, as well as the related disorders, have been exclusively considered.     

Modulation of bile acid profile by gut microbiota in chronic hepatitis B

Chronic hepatitis B (CHB) is a global epidemic disease that may progress to fibrosis, cirrhosis and hepatocellular carcinoma. The role of the liver‐bile acid‐microbiota axis in CHB remains unclear. The aims of this study are to elucidate the alteration of the gut microbiota and its functions in bile acid homeostasis in CHB patients with different degrees of fibrosis. In the present study, we evaluated serum and faecal bile acid profiles in healthy controls and CHB patients with biopsy‐proven diagnosis: patients had stage 0‐1 fibrosis were classified as mild CHB and patients had stage 2‐4 fibrosis were classified as moderate/advanced CHB. The levels of serum total bile acids (BAs) and primary BAs were increased in CHB patients with moderate/advanced fibrosis, whereas faecal total and secondary BAs levels were significantly lower. Analyses of gut microbiota exhibited a trend of decreased abundance in bacteria genera responsible for BA metabolism in CHB patients with moderate/advanced fibrosis. CHB is associated with altered bile acid pool which is linked with the dysregulated gut microbiota. The higher level of FGF‐19 may act in a negative feedback loop for maintaining the bile acid homeostasis.     

肠道微生物与骨质疏松相关性的研究进展

随着人口老龄化问题的加剧,骨质疏松症的高发生率降低了人们的生活质量。越来越多的证据表明,肠道微生物群与骨代谢联系密切,肠道微生物群稳态的破坏会导致宿主的病理生理反应,从而引起骨质疏松。通过研究两者之间的相互作用,或许能为骨质疏松症的预防及相关诊疗提供有价值的帮助。本文就目前肠道微生物与骨质疏松症相关机制和主要治疗的研究现状作一综述。