利用eLSA算法研究抗生素对人类肠道微生物菌群的影响

人类肠道微生物与人体健康有着千丝万缕的联系,肠道微生物群的改变是人体健康及功能的标志物。本文利用eLSA算法研究抗生素对人体肠道微生物菌群之间关联的影响,结果表明：抗生素对肠道微生物的影响,不仅出现在全局的时间序列关联中,同时还出现在局部和带时间延迟的关联序列中;肠道微生物经历重复的抗生素扰动时,部分扰动反应关联消失或出现新的关联,说明抗生素的扰动可以改变肠道微生物菌群间原有的状态,这种改变甚至有可能是长期的;个体拥有的肠道微生物并不完全相同,不同的个体对应同样的抗生素扰动会有不同的个性化反应。     

禽类肠道主要APUD细胞分布及其生理功能的研究进展

禽类动物肠道中存在许多能够分泌肽类激素的内分泌细胞(Amine Precursor Uptake and Decarboxylation Cells,APUD细胞),主要包括S细胞、G细胞、D细胞、PP细胞、I细胞、L细胞、N细胞、M细胞、K细胞,它们分别释放肠促胰液素、胃泌素和脑啡肽、生长抑素和血管活性肠肽、禽胰多肽、缩胆囊素、肠高血糖素、神经降压素、胃动素、葡萄糖依赖性促胰岛素多肽等相关激素,在禽类动物肠道的营养、消化吸收和免疫功能等方面发挥着重要的作用.对禽类肠道主要APUD细胞的种类、分布及生理功能的研究概况进行综述,为深入研究禽类肠道的生理功能提供参考.     

基于高通量测序的不同养殖系统下凡纳滨对虾肠道和水体中微生物的多样性

【目的】研究不同养殖系统对凡纳滨对虾肠道及水体微生物多样性的影响。【方法】以循环养殖系统和非养殖系统下凡纳滨对虾养殖水体及其肠道为研究对象,在养殖30d后采集样品,采用Illumina MiSeq高通量测序样品细菌16SrRNA基因V3+V4区,通过RDP11.3、Greengenes13.8、NCBI 16S Microbial和Customized batabase等数据库进行分析,阐述循环养殖系统的意义和微生物在其中的作用。【结果】养殖期间,不同养殖系统凡纳滨对虾均正常存活。将原始序列优化后对Clean序列进行分析,非循环系统下水体优质序列百分比约81%,肠道中约89%;循环系统下水体优质序列百分比为92%,肠道中为94%。两种养殖系统下水体和肠道细菌在纲水平占绝对优势的是变形菌纲,但各菌群丰度不同;不同的Alpha指数显示出物种间的差异性;通过系统发育树可以看出,不同养殖系统改变了凡纳滨对虾生境中的物种及发育关系,间接阐述微生物在养殖生境中的作用和意义。【结论】通过高通量测序揭示不同养殖系统中微生物菌群的差异以及多样性,对于凡纳滨对虾实际养殖具有指导作用,对阐述养殖过程中微生物和相关疾病的关系具有重要意义。     

支气管哮喘患者肠道菌群多样性变化

 为了阐释支气管哮喘患者肠道菌群多样性及结构组成特征,探究肠道菌群与哮喘病的相互关系,以52例哮喘急性发作期患者及25例对照开展病例-对照研究.采集粪便样品,运用PCR-DGGE指纹图谱技术分析粪便菌总DNA,得到反映肠道微生物菌群结构特征的DNA指纹图谱.结果表明,哮喘个体样本的肠道菌DNA条带数量7—31条不等,平均只有17条;对照组样本个体的DNA条带数量14—36条不等,平均24条.哮喘患者肠道菌群的Shannon-Wiener多样性指数显著低于对照组(P＜0.0001).多变量统计分析表明,哮喘组肠道菌群结构组成显著区别于对照组,两组样本分类明显.两组内不同民族、性别间的差异无统计学意义.研究表明,哮喘患者的肠道菌群在分子水平上发生明显改变,多样性显著降低,肠道菌群结构改变与哮喘病有关;PCR-DGGE技术结合PCA、PLS-DA多变量统计分析手段具有预测性、先行性的优势,适用于菌群结构未知样品的研究.     

Food spectrum analysis of the Asian toad,Duttaphrynus melanostictus (Schneider, 1799) (Anura: Bufonidae), from Timor Island,Wallacea

The Asian toad, Duttaphrynus melanostictus (Schneider, 1799), is widespread throughout tropical Asia and very abundant where it occurs. It was relatively recently introduced to Timor, the second largest island in the biogeographic region called Wallacea. Timor Island shows an exceptionally high level of endemism in a wide range of faunal groups and there are concerns that D. melanostictus may have a negative impact on this diversity, including vertebrates, through direct predation. To evaluate the impact the diet of D. melanostictus might have on the local fauna, gut contents of 83 preserved toad specimens from five habitat types in Timor-Leste, a country occupying the eastern half of Timor Island, were examined. We identified 5581 prey items, comprising the following animal groups: annelids; snails and slugs; spiders and harvestmen; woodlice; millipedes and centipedes; grasshoppers, crickets and earwigs; termites; thrips and true bugs; beetles; ants; hymenopterans other than ants; true flies; butterflies; unidentified insects; and insect larvae. Small eusocial insects (ants and termites) constituted the major part of the diet (61.6% and 23.4%, respectively). No vertebrate prey was recorded. Prey item composition did not differ between habitats. The wide prey spectrum well indicates that D. melanostictus is a generalist invertebrate feeder, as other studies, from regions where this species occurs naturally, have already shown. Although the Asian toad seems to not generally prey on vertebrates, vertebrate species that are morphologically similar to invertebrates in their overall appearance may be consumed. Hence, a negative effect on some taxa (e.g. blindsnakes) may be possible. We also present some limited data on intestinal parasites occurring in D. melanostictus.     

水体铜对鲤肠道菌群结构及免疫力的影响

为了解水体重金属铜对鲤肠道菌群多样性、结构及免疫力的影响,以不同质量浓度的水体铜胁迫鲤56d,对鲤肠道菌群α多样性、β多样性、基于属水平的群落组成结构及肠道免疫调控因子和紧密连接蛋白的基因表达进行了分析.结果显示,0.14mg·L-1、0.28mg·L-1处理组与对照组相比,α多样性指数有显著性下降(P0.01),主成分分析(PCA)显示两处理组与对照组群落组成区分明显,优势菌群发生明显变化;同时,两处理组肠道免疫调控因子Il-1β,IL-8,TNF-α及信号分子NF-κB基因表达有显著增加(P0.01),肠道紧密连接蛋白Claudin-3,Claudin-c及免疫调控因子IL-10、信号分子TOR基因表达有显著下降(P0.01).结果表明:中、高质量浓度水体铜胁迫显著降低了鲤肠道菌群的多样性,改变了结构组成,对鲤肠道上皮免疫屏障造成了损伤.     

小鼠原始生殖细胞的发生部位和迁移路线的初步研究

我们用碱性磷酸酶法对小鼠原始生殖细胞的发生部位和迁移路线进行了研究。在7天18小时的胚胎中没有发现原始生殖细胞,至8天8小时,在尿囊柄基部和原条尾端出现了成群集中的原始生殖细胞,这时原始生殖细胞总数目不超过100个。9天,原始生殖细胞沿后肠在肠壁内胚层细胞之间向前迁移。9天10小时部分原始生殖细胞进入背肠系膜。甲苯胺蓝染色显示原始生殖细胞嗜碱性强,与周围体细胞有着明显差别,其分布位置与碱性磷酸酶法显示出的位置一致。本实验表明,小鼠原始生殖细胞的最早出现部位是在尿囊柄基部。     

The Effects of Shrimp Gut Probiotic Bacteria on the Shrimp Larvae (Penaeus Chinensis)

The survival rates of shrimp larvae in different stage are higher than those of control groups when probiotic bacteria strains X4B-1 and X1B-1 which are isolated from gut of adult shrimp are added into the little volume rearing sea water of shrimp larvae. The effects of probiotic bacteria are evaluated by challenge test (pathogenic bacteria Z3G2 isolated from disease shrimp larvae in the hatchery of Jimo town) and low salinity stress resistance tests on shrimp larvae, the survival rate and lengths of the shrimp larvae in the experiment are determined. Results indicate that 1. The survival rate, ability of resistant to low salinity, lengths of the delivered shrimp larvae are improved after the strains of probiotic bacteria, X4B-1 or X1B-1, are added into the rearing sea water of hatchery. 2. The addition of the probiotic bacteria could not influence the change of the bacteria number, NH3-N and COD value in the rearing sea water. 3. The probiotic bacteria used in the experiment have many enzymes such as Lipase, Amylase, Gelatinase and Lecithinase. These enzymes may help the probiotic bacteria to digest the food components fed to shrimp larvae and increase the digestive efficiency of post larvae. This may be one of the reasons why these probiotic bacteria are beneficial to the shrimp larvae.     

人体的胃肠道微生态系统和微生态失衡

人体出生时胃肠道是无菌的,但几小时后就发生细菌在胃肠道内的定植、演替过程,最终形成相对稳定的微生物群落.这些细菌大多是有益的,对人体维持正常的生理功能有重要的作用.     

树枝状聚合物PAMAM葛根素复合物的制备及肠吸收研究

制备树枝状聚合物G3,G4,G5 PAMAM葛根素复合物,研究其在大鼠不同肠段的吸收情况.采用大鼠离体外翻肠囊法、高效液相色谱法测定葛根素大鼠小肠吸收参数,以未加PAMAM组作为空白对照组,计算累积透过量及表观通透系数(Papp).葛根素在空肠及回肠段吸收明显,表观通透系数分别为(2.98±0.22)×10-6、(3.94±0.30)×10-6cm·s-1,PAMAM与葛根素形成复合物能增加葛根素大鼠小肠累积透过量及表观通透系数.其中G5 PAMAM对葛根素促进作用最为显著,葛根素空肠、回肠段表观通透系数分别增加了2.78、2.22倍(P＜0.05).PAMAM能有效促进葛根素大鼠小肠吸收.