哺乳仔猪断奶前后肠道微生物培养组学研究

近年来国内外研究人员通过下一代测序和分离培养技术,结合宏基因组学相关的生物信息学手段证实了猪肠道微生物的组成及其代谢物活性对宿主的健康具有重要作用。受限于传统培养方法,猪肠道中大多数细菌仍无法培养,因此,为了突破研究人员研究宿主-菌株相互关系及益生菌株开发应用的限制,本研究对仔猪断奶前后回肠和结肠内容物微生物进行高通量培养组学研究。结合需氧和厌氧条件、不同培养时间以及25种不同培养基,共筛选获得1385株厌氧、好氧和兼性厌氧菌株,并全部进行了16S rRNA全长测序鉴定和菌株保存,共计获得5个门、29个属和86个种菌,其中包含梭杆菌、拟杆菌等在以前的研究中较难分离获得的菌株,以及一些如乳酸菌等具有潜在应用价值的益生菌,更为重要的是其中包含116株疑似新菌种。本研究获得的菌株信息可以进一步完善猪肠道微生物物种数据库,为后续宿主-菌株相互关系研究垫定了基础,对猪饲用益生菌相关产品开发研究具有重要意义。     

培养组学在动物肠道微生物应用的研究进展

肠道微生物被称为动物的“隐藏免疫器官”,不仅能参与宿主代谢还能影响宿主的免疫系统,对维持机体健康至关重要。作者主要介绍了培养组学的发展历程及其对动物肠道微生物研究的重要意义、传统微生物培养方法和分子生物学方法在研究微生物时各自的优、缺点。培养组学是基于传统微生物培养方法同时采用多种培养条件进行微生物培养,再辅以基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)和16S rRNA基因测序技术建立的一种新型微生物分离、鉴定方法,该方法将传统微生物培养技术与分子生物学技术的优点融为一体。该方法在挖掘“新微生物”的研究中,具有发现、找到并获得的优势;在微生物的研究中可定制分离目标菌株进行验证,并能通过丰富注释清楚地了解肠道微生物组。此外,分析了培养组学分别在家禽肠道、猪肠道、反刍动物肠道等动物肠道的研究应用现状,提出了环境条件对肠道微生物的影响,如人类接触对肠道菌群的影响、同物种不同性别肠道菌群的差异,以期为培养组学在动物肠道微生物的研究运用中提供参考。     

浅谈蜜蜂的肠道菌群

正肠道菌群在动物健康中的重要地位渐渐被人们所熟知,也越来越受到科学家的关注。在人类肠道菌群的研究中,不仅仅证实了肠道菌群与疾病的相关性,也验证了肠道菌群与长寿的显著关系。肠道是一个很复杂的无氧环境,虽然科学家们通过在体外模仿肠道的环境,以及筛选培养基的使用,筛选出了大量的肠道细菌,但是大多数的肠道菌群还是没法通过体外培养获得。由于高通量测序技术的快速发展和应用,加速了我们对肠道菌群的组成、定植规律以及功能的深     

肠道菌群功能及检测技术研究进展

大量的微生物存在于动物的胃肠内,在经过长期的进化与选择之后,它们形成了一个动态的微生物系统。肠道菌群与机体的相互作用对动物本身来说十分重要,近年来更是已经成为研究的热点问题。肠道菌群的功能主要体现在它对机体的生物屏障作用、营养作用、免疫作用等方面。肠道菌群的检测方法是研究肠道菌群的重点和难点问题,目前主要技术有分离培养、质谱技术、宏基因组测序等。文章结合大量文献资料,总结了目前肠道菌群功能的相关研究成果及研究方法。     

转录组测序及其在猪上的研究进展

转录组学是研究基因结构和功能的重要研究方法,其中RNA-seq测序技术的快速发展使得转录组学日益成为分子生物学和功能基因组学的重要组成成员。转录组测序技术是转录组学研究的重要基础,该技术关系着能否高效、准确地识别转录组信息,因而关乎着转录组分析的可行性。基因转录组测序技术的转录组学分析已经在猪、牛等畜种上有所运用,丰富了畜牧学的研究。文章主要对转录组测序的相关概念以及其在猪上的运用进行综述。     

梅花鹿肠道细菌菌群多样性的PCR-DGGE分析方法的建立

为建立梅花鹿肠道细菌菌群多样性PCR-DGGE分析方法,并分析鹿肠道细菌菌群结构和菌群多样性,试验抽提了采自吉林农业科技学院左家校区的梅花鹿肠道菌群样本DNA,使用细菌原核通用引物F357-GC和R518进行PCR扩增,经变性梯度凝胶电泳与DNA测序技术对所得到的目的片段进行分析。结果表明:梅花鹿肠道内可检出多个相似菌种,PCR-DGGE分析方法可用于梅花鹿肠道菌群分析研究。     

应用高通量测序技术检测无特定病原体鸭粪便的微生物多样性

高通量测序技术在动物肠道微生物研究中发挥着重要作用。从3株(9个样品)无特定病原体(SPF)鸭子中收集的粪便样品放置在培养箱中培养。利用Illumina HiSeq2500平台,通过16S rRNA测序的不同区域来分析鸭肠道细菌区系。结果表明,70周龄SPF鸭的肠道微生物丰度最高的三个门是厚壁菌门、变形杆菌门和拟杆菌门,丰度最高的三个目为梭菌目、乳杆菌目和气单胞菌目,丰度最高的三个属为拟杆菌属、丛孢菌属和肠球菌属。此外,3株鸭菌株具有不同的微生物组成,但这些差异不显著。采用高通量测序方法对鸭肠道菌群进行分析,以进一步了解SPF鸭肠道菌群的分布和生物学特性,最终有利于SPF鸭的纯化。     

微生物制剂对小龙虾肠道菌群结构的影响北大核心

研究旨在探索微生物制剂对小龙虾肠道菌群结构的影响。利用从小龙虾肠道中分离得到的枯草芽孢杆菌CP-3,制备CP-3菌剂,结合乳酸菌菌剂、酵母菌菌剂制备微生物制剂;采用含微生物制剂的饵料投喂小龙虾,高通量测序分析小龙虾肠道菌群结构变化。结果显示,与未添加微生物制剂组相比,微生物制剂组的小龙虾肠道内细菌生物多样性和物种丰富度均明显增加,肠道内菌群结构也改变较大。各组小龙虾肠道的优势菌群均为变形菌门,微生物制剂组小龙虾的厚壁菌门细菌含量由6.10%提高至14.21%,有害菌群弧菌属数量由10.11%降低至4.68%。研究表明,投喂微生物制剂饵料可影响小龙虾肠道细菌群落的生长,小龙虾肠道菌群更趋向丰富和稳定。     

人工饲料对柞蚕幼虫肠道菌群多样性的影响

为研究人工饲料对柞蚕幼虫肠道菌群组成、多样性特征及菌群功能的影响,收集从收蚁开始分别饲育柞树叶和人工饲料至2龄时期的柞蚕肠道样品,通过高通量测序技术对其肠道微生物进行分析,并采用Tax4Fun软件预测菌群潜在功能。结果发现,不同饲育组柞蚕幼虫肠道菌群结构存在显著差异,人工饲料组柞蚕幼虫肠道菌群多样性低于柞树叶组。肠道菌群功能预测结果显示,人工饲料组肠道菌群中翻译、复制和修复、能量代谢、辅助因子和维生素代谢等功能基因丰度显著升高,在碳水化合物代谢、膜运输等功能基因丰度显著降低。结果表明人工饲料显著改变了柞蚕肠道的菌群结构组成,并影响其代谢功能,这些变化可能与柞蚕幼虫生长缓慢、体质量减轻有关。     

猪肠道微生物组成、影响因素及其对重要经济性状的影响研究进展

肠道微生物在调节宿主生理机能、代谢和免疫功能等方面发挥着非常重要的作用,是影响猪健康和重要经济性状表型的重要因素之一。近年来,人们对猪肠道微生物的研究和了解越来越深入,了解猪肠道微生物组成将有助于为从肠道菌群方向入手改善猪群健康和提高生产性能提供参考。作者首先综述了不同发育阶段、不同肠道部位以及主要商品猪和中国地方猪肠道核心菌群组成;其次系统总结了宿主遗传背景、饲粮种类、性别、环境以及抗生素、益生菌和饲料添加剂使用等因素对猪肠道微生物组成的影响;最后概述了猪肠道微生物主要功能及其对饲料利用率、脂肪沉积、宿主行为和免疫炎症等方面的影响。     

猪肠道微生物及其代谢产物与肠道屏障研究进展

肠道微生物参与营养物质代谢，影响猪的健康和发育，当肠道微生物发生紊乱，会造成猪腹泻并引起炎症反应，因此肠道微生物对猪的健康起着至关重要的作用。本文从肠道微生物在仔猪不同发育阶段的分布、肠道微生物的代谢产物对肠道健康的影响机制和肠道微生物与肠道屏障之间的关系进行阐述，并探讨了目前肠道健康研究的进展以及今后的研究方向，旨在为猪肠道健康调控提供理论参考。     

Relationship between gut microbiota and host-metabolism: Emphasis on hormones related to reproductive function

It has been well recognized that interactions between the gut microbiota and host-metabolism have a proven effect on health. The gut lumen is known for harboring different bacterial communities. Microbial by-products and structural components, which are derived through the gut microbiota, generate a signaling response to maintain homeostasis. Gut microbiota is not only involved in metabolic disorders, but also participates in the regulation of reproductive hormonal function. Bacterial phyla, which are localized in the gut, allow for the metabolization of steroid hormones through the stimulation of different enzymes. Reproductive hormones such as progesterone, estrogen and testosterone play a pivotal role in the successful completion of reproductive events. Disruption in this mechanism may lead to reproductive disorders. Environmental bacteria can affect the metabolism, and degrade steroid hormones and their relevant compounds. This behavior of the bacteria can safely be implemented to eliminate steroidal compounds from a polluted environment. In this review, we summarize the metabolism of steroid hormones on the regulation of gut microbiota and vice-versa, and also examined the significant influence this process has on various events of reproductive function. Altogether, the evidence suggests that steroid hormones and gut microbiota exert a central role in the modification of host bacterial action and impact the reproductive efficiency of animals and humans.     

Carbohydrates effects on nutrition and health functions in pigs

The greatest improvement in carbohydrates studies on pig nutrition and health is that carbohydrates are classified more clearly, which is based not only on their chemical structure but also on their physiological characteristics. Besides its primary energy source, different types and structures of carbohydrates are a benefit for nutrition and health functions in pigs, which are involved in promoting growth performance and intestinal functions, regulating the community of gut microbiota, and modulating the lipids and glucose metabolism. The underlying mechanism of carbohydrates regulates the lipids and glucose metabolism through their metabolites (short-chain fatty acids [SCFAs]) and mainly via the SCFAs-GPR43/41-PYY/GLP1, SCFAs-AMP/ATP-AMPK, and SCFAs-AMPK-G6Pase/PEPCK pathways. Emerging research had evaluated an optimal combination in different types and structures of carbohydrates, which could enhance growth performance and nutrient digestibility, promote intestinal functions, and increase the abundances of butyrate-producing bacteria in pigs. Overall, compelling evidence supports the notion that carbohydrates play important roles in both nutrition and health functions in pigs. Moreover, identifying the carbohydrates combinations will be of both theoretical and practical values for developing the technology of carbohydrates balance in pigs.     

First isolation of Haemophilus parasuis and other NAD-dependent Pasteurellaceae of swine from European wild boars

Haemophilus parasuis is a colonizer of the upper respiratory tract of pigs and the etiological agent of Gl?sser's disease, which is characterized by a fibrinous polyserositis, meningitis and arthritis. Gl?sser's disease has never been reported in wild boar (Sus scrofa), although antibodies against H. parasuis have been detected. The goal of this study was to confirm the presence of this bacterium in wild boar by bacterial isolation and to compare the strains to H. parasuis from domesticated pigs. Therefore, nasal swabs from 42 hunted wild boars were processed for bacterial isolation and subsequent H. parasuis identification by specific PCR, biochemical tests and 16S rRNA gene sequencing. Two different strains of H. parasuis from two wild boars were isolated. These strains belonged to serotype 2 and were included by 16S rRNA gene sequencing and MLST analysis in a cluster with other H. parasuis strains of nasal origin from domestic pigs. During this study, Actinobacillus minor and Actinobacillus indolicus, which are NAD-dependent Pasteurellaceae closely related to H. parasuis, were also isolated. Our results indicate similarities in the respiratory microbiota of wild boars and domestic pigs, and although H. parasuis was isolated from wild boars, more studies are needed to determine if this could be a source of H. parasuis infection for domestic pigs.     

The effects of dietary reduced mineral elements and coated cysteamine supplementation on bacterial diversity in the ileum of finishing pigs

This study was conducted to investigate the effects of different levels of dietary partial MEs and coated cysteamine (CC) supplementation on gut microbiota in finishing pigs. Results showed that whittling down dietary partial MEs (Cu, Fe, Zn, Mn) by 20% and 40% had little effect on the microbial diversity, community structure, and bacterial relative abundance in the ileum of finishing pigs. Supplementation with 1,600 mg/kg CC also had no obvious effect on the microbial diversity, community structure, and bacterial relative abundance in the finishing pig ileum when fed diets with a normal MEs level. However, the abundance of Peptostreptococcaceae, Pasteurella, and Pasteurella_aerogenes was higher, and the abundance of Actinobacillus_minor was lower in the 20% ME reduction diet treatment than that in the 20% ME reduction with 1,600 mg/kg CC diet group (p < 0.05). In conclusion, our results suggested that there is no obvious effect on gut microbiota when dietary partial MEs are reduced by 20% or 40%, which indicates the feasibility of reducing dietary partial MEs by 20% or 40% in finishing pigs. Supplementation with CC changed the relative abundance of some bacteria related to opportunistic pathogenicity in the finishing pig ileum when were fed a 20% ME reduction diet.     

A defined intestinal colonization microbiota for gnotobiotic pigs

Maximising the ability of piglets to survive exposure to pathogens is essential to reduce early piglet mortality, an important factor in efficient commercial pig production. Mortality rates can be influenced by many factors, including early colonization by microbial commensals. Here we describe the development of an intestinal microbiota, the Bristol microbiota, for use in gnotobiotic pigs and its influence on synthesis of systemic immunoglobulins. Such a microbiota will be of value in studies of the consequences of early microbial colonization on development of the intestinal immune system and subsequent susceptibility to disease. Gnotobiotic pig studies lack a well-established intestinal microbiota. The use of the Altered Schaedler Flora (ASF), a murine intestinal microbiota, to colonize the intestines of Caesarean-derived, gnotobiotic pigs prior to gut closure, resulted in unreliable colonization with most (but not all) strains of the ASF. Subsequently, a novel, simpler porcine microbiota was developed. The novel microbiota reliably colonized the length of the intestinal tract when administered to gnotobiotic piglets. No health problems were observed, and the novel microbiota induced a systemic increase in serum immunoglobulins, in particular IgA and IgM. The Bristol microbiota will be of value for highly controlled, reproducible experiments of the consequences of early microbial colonization on susceptibility to disease in neonatal piglets, and as a biomedical model for the impact of microbial colonization on development of the intestinal mucosa and immune system in neonates.     

民猪肠道菌群特征分析

试验旨在解析不同月龄民猪的肠道菌群特征及粗纤维对民猪肠道微生物的影响。选择5头体重为(100±7.24)kg的10月龄成年母猪(成年组)和(50±4.31)kg的6月龄青年母猪(青年组),青年组又分为正常饲喂组(5头)和添加粗纤维组(4头),采集同一时间、新鲜的粪便样品,提取总DNA,利用带标签的通用引物扩增16S rRNA V4区,使用Illumina Hiseq 2000测序平台测序,通过计算Ace和Shannon多样性指数以及与已知数据库的比对,分析菌群多样性及结构特征。结果表明:3个处理组在菌群多样性方面无显著差异(P0.05);3组均以拟杆菌门、厚壁菌门和螺旋菌门所占的比例最高,总计可达91%~92%,粗纤维的添加明显改变了青年组肠道微生物的组成,大幅提升了拟杆菌门所占的比例,降低了厚壁菌门和螺旋菌门所占的比例,使其菌群分布比例更接近成年个体;同时,粗纤维的添加也促进了肠道微生物内纤维杆菌属的增加。