虹鳟肠道微生物的研究进展

虹鳟肠道微生物群落是肠道的正常组成部分,与肠道共同构成了具有一定生理功能的微生态系统,在宿主的生长发育、营养代谢、免疫调节和防御等方面发挥了不可替代的作用,对虹鳟的健康生长十分重要。本文对虹鳟肠道微生物的组成及其在营养、屏障和免疫等方面的功能,以及影响肠道微生物的因素进行了综述,旨在为更深入地研究虹鳟肠道微生物提供理论参考。     

肉鸡肠道微生物及其调控

近年来,肉鸡肠道微生物已被广泛研究,它对宿主的健康和生产性能等方面发挥了重要的作用,尤其是在免疫防御以及营养生理中产生积极影响。随着促生长类抗生素的禁止使用,通过调控肠道微生物菌群改善肉鸡的生长与免疫成为解决抗生素替代问题的有效途径。本文从肉鸡肠道微生物的组成、分布、功能、影响因素及调控技术方面进行了综述。     

宏基因组技术在鸡肠道微生物中应用的研究进展

鸡肠道中生存着丰富的微生物,这些微生物在宿主的营养代谢与免疫方面有重要作用。高通量测序技术的发展为肠道微生物的研究提供了新的思路,文章简要介绍了宏基因组学,阐述肠道微生物结构变化对宿主的影响及不同饲养条件、宿主生理特征改变对肠道微生的影响,并重点从宏基因组的层面透析鸡肠道微生物菌落结构、营养代谢特征、免疫功能与鸡的健康生长之间的关联性,以期为鸡肠道微生物的研究提供思路。     

家蚕肠道微生物的研究进展

家蚕肠道中存在着丰富的微生物群体,肠道微生物在家蚕消化吸收和抵御外界病原菌等方面都扮演着重要的角色,随着家蚕的生长发育,其肠道微生物也不断的变化,优势菌群的分布与家蚕的正常生长息息相关.文章从家蚕肠道微生物的组成、功能、影响因素和昆虫肠道微生物研究进展进行了阐述,以期为今后的家蚕乃至昆虫肠道微生物研究提供参考.     

水禽肠道微生物及其研究进展

动物的肠道内有复杂而动态的微生物生态系统,这些微生物通过促进营养摄取、宿主防御、免疫调节等,在维持机体健康方面起着至关重要的作用。菌落的结构组成因母体、饲粮、环境、生理状态变化及自身菌种间互作等因素而不同。水禽(鸭和鹅)属于卵生动物,与哺乳动物相比,其肠道的微生物系统具有特殊性。作者介绍了水禽肠道微生物的建立、肠段不同部位的微生物群结构组成特征及发育性变化,从肠道微生物对水禽生长性能、养分消化吸收的影响,以及与免疫系统的关系3个方面阐述了水禽肠道微生物的主要功能,同时通过饲粮组成、动物体生理状态、外界环境因素、微生物自身因素及互作等4个方面分析了影响水禽肠道微生物的多重因素,并对水禽肠道微生物今后的研究思路及发展方向进行了展望,以期为养殖中饲料配方设计、改善肠道健康、提高生产效益等提供理论依据,从而为从肠道微生物这一崭新靶点精准调控水禽的营养、免疫和生长过程,以及水禽肠道微生物的进一步深入研究提供借鉴。     

家禽肠道微生物稳定性影响因素及其生理功能研究进展

家禽肠道微生物可以参与宿主食物消化与营养吸收,刺激免疫系统的发育和成熟,抵抗病原菌。家禽肠道微生物易受到诸多因素的影响(遗传、环境、饮食与添加剂、日龄等)。维持肠道微生物群落状况与多样性是保证其发挥正常生理功能的前提。在前人研究的基础上,本文旨在概述家禽肠道微生物的优势菌群及其生理功能,并总结影响家禽肠道微生物组成的主要因素,以期为家禽肠道微生物的研究及家禽领域的遗传育种研究提供新思路。     

肠道微生物调控动物肌肉的生长和发育北大核心CSCD

栖息于动物肠道中的微生物群与宿主形成稳定的共生关系。肠道菌群的定植状态、繁殖能力和营养需求受到宿主生理稳态的影响,同时,肠道菌群的组成和多样性随宿主外部和内部环境的改变而发生波动。此外,肠道菌群通过肠道神经系统和外周循环系统直接或间接参与并调控宿主的信号传递、物质代谢、免疫形成和器官功能。骨骼肌的生长、发育和代谢很大程度上决定了动物的能量稳态和整体生长性能,是决定动物产肉性状和肉品生产的根本因素。当前,大量研究表明动物肠道微生物在促进肌肉生长和维持肌肉机能方面发挥重要作用,一些学者提出了"肠-肌轴"的双向信息交流机制。本文综述了近年来国内外关于消化道微生物参与调控人和动物的肌肉生长和发育、肌肉疾病形成、物质与能量代谢等方面的研究进展,加深和完善关于肠道微生物调控肌肉生长和发育的认识。     

仔猪肠道微生物代谢产物及益生菌的调控作用

近年来,肠道微生物组成及其代谢产物与宿主生理之间的互作关系成为当前动物营养研究的热点。研究表明,肠道微生物的代谢产物是影响宿主生理的关键执行者,肠道微生物具有调节宿主代谢、免疫、生长发育等作用。本文系统地综述了仔猪肠道微生物组成、代谢产物种类和功能,以及益生菌对仔猪肠道微生物的影响,以期为仔猪营养调控和肠道微生物的研究提供科学依据。     

肠道微生物与宿主遗传背景互作关系的研究进展

哺乳动物的肠道寄居着大量而且种类繁多的微生物,它们受到宿主基因和环境尤其是食物的影响。近年来,随着宏基因组的出现和测序技术的不断发展,关于人和其他动物的肠道微生物研究日益深入。肠道微生物与人类肥胖和Ⅱ型糖尿病相关性的发现等,进一步加强了科学界对于肠道微生物的关注度。然而,对于肠道微生物与宿主的密切联系以及相互作用机制仍然需要深入研究。本文简要论述了肠道微生物对宿主的功能贡献和宿主的遗传背景对肠道微生物的影响。     

肠道寄生虫与肠道微生物相互作用研究进展

在脊椎动物的肠道内，存在着数量庞大、结构多样、动态变化的微生物群，它们对肠道的生理、代谢、免疫等具有重要的作用。在自然条件下，这些微生物和真核生物(如蠕虫、原生动物、真菌等)共同存在于脊椎动物肠道内。寄生虫与微生物群均可显著改变机体肠道生理与免疫环境，为它们之间的相互作用创造了机会。肠道微生物与寄生虫之间的相互作用会极大地影响感染的结果，进而对宿主的健康产生重要影响。如寄生虫感染会影响宿主与微生物的相互作用关系，从而促使或保护宿主免受细菌的侵害。另一方面，菌群又会影响寄生虫的定植、繁殖和毒性，使其沿着与宿主寄生性-互惠共生性的生存模式发展。这些相互作用的机理与结果是微生物学与寄生虫学之间交叉研究的前沿课题。笔者对近年来有关肠道寄生虫与肠道微生物间相互作用的最新研究成果进行了总结，并对其可能未考虑到的因素提出了自己的观点，旨在为肠道寄生虫病防控及肠道菌群研究提供参考。     

Opportunities of prebiotics for the intestinal health of monogastric animals

The goal of prebiotic applications from different sources is to improve the gut ecosystem where the host and microbiota can benefit from prebiotics. It has already been recognized that prebiotics have potential roles in the gut ecosystem because gut microbiota ferment complex dietary macronutrients and carry out a broad range of functions in the host body, such as the production of nutrients and vitamins, protection against pathogens, and maintenance of immune system balance. The gut ecosystem is very crucial and can be affected by numerous factors consisting of dietary constituents and commensal bacteria. This review focuses on recent scientific evidence, confirming a beneficial effect of prebiotics on animal health, particularly in terms of protection against pathogenic bacteria and increasing the number of beneficial bacteria that may improve epithelial cell barrier functions. It has also been reviewed that modification of the gut ecosystem through the utilization of prebiotics significantly affects the intestinal health of animals. However, the identification and characterization of novel potential prebiotics remain a topical issue and elucidation of the metagenomics relationship between gut microbiota alteration and prebiotic substances is necessary for future prebiotic studies.     

Influences of quorum‐quenching probiotic bacteria on the gut microbial community and immune function in weaning pigs

The aim of this study is to investigate the dynamic gut microbial diversity in weaning swine after administering feed supplemented with probiotic bacteria that specifically inhibit the activity of quorum molecules. Initially, the universal quorum molecule autoinducer‐2 (AI‐2) bioassay results indicated that AI‐2 activity was profoundly inhibited in enterohemorrhagic Escherichia coli (EHEC) O157:H7 in the presence of Lactobacillus acidophilus strain 30SC cell extract, although the growth of EHEC was not affected. Based on plate counting results, bacterial community analysis revealed a specific reduction in coliforms compared to the control, whereas the population of lactobacilli increased in weaning swine in in vivo trials. Supplementation with L. acidophilus strain 30SC did not affect the counts of other communities, such as total aerobes and yeast/mold. In addition, PCR‐denaturing gradient gel electrophoresis analysis showed a significant difference in the 16S rRNA gene products after administering L. acidophilus strain 30SC. Selected bands were sequenced, and most of them were identified as uncultured bacterium clones or a Lactobacillus‐ and Bifidobacterium‐specific community. Therefore, our results indicate that quorum‐quenching probiotic bacteria can significantly modulate the gut microbiota of swine and these beneficial effects can contribute to the improvement of performance and health in the gastrointestinal tract of weaning pigs.     

Gut microbes limit growth in house sparrow nestlings (Passer domesticus) but not through limitations in digestive capacity

Recent research often lauds the services and beneficial effects of host‐associated microbes on animals. However, hosting these microbes may come at a cost. For example, germ‐free and antibiotic‐treated birds generally grow faster than their conventional counterparts. In the wild, juvenile body size is correlated with survival, so hosting a microbiota may incur a fitness cost. Avian altricial nestlings represent an interesting study system in which to investigate these interactions, given that they exhibit the fastest growth rates among vertebrates, and growth is limited by their digestive capacity. We investigated whether reduction and restructuring of the microbiota by antibiotic treatment would: (i) increase growth and food conversion efficiency in nestling house sparrows (Passer domesticus); (ii) alter aspects of gut anatomy or function (particularly activities of digestive carbohydrases and their regulation in response to dietary change); and (iii) whether there were correlations between relative abundances of microbial taxa, digestive function and nestling growth. Antibiotic treatment significantly increased growth and food conversion efficiency in nestlings. Antibiotics did not alter aspects of gut anatomy that we considered but depressed intestinal maltase activity. There were no significant correlations between abundances of microbial taxa and aspects of host physiology. Overall, we conclude that microbial‐induced growth limitation in developing birds is not driven by interactions with digestive capacity. Rather, decreased energetic and material costs of immune function or beneficial effects from microbes enriched under antibiotic treatment may underlie these effects. Understanding the costs and tradeoffs of hosting gut microbial communities represents an avenue of future research.     

家蚕miRNA及其在抗病毒机制中的作用

miRNA广泛存在于真核生物中,并在多种生理过程中发挥着重要的作用。本文简要介绍了家蚕miRNA及其在抗病毒机制中功能作用的研究进展。开展家蚕miRNA在家蚕抗病毒作用机制的研究,不仅有助于全面了解家蚕miRNA的功能及其调控机制,而且对于促进家蚕病毒病的早期诊断、防治和抗病育种具有重要意义。     

The effect of fly maggot in pig feeding diets on growth performance and gut microbial balance in Ningxiang pigs

Fly maggot meal has been regarded as one of the substitutes of fish meal and soybean meal in pig feed. However, its effects on pig growth performance and faecal micro-organism remain unclear. The purpose of this study was to investigate the effect of dietary fly maggot meal on fattening performance, plasma indices related to gut hormones, immunity and faecal microbial communities composition of finishing pigs. A total of 40 Ningxiang fattening pigs were randomly allocated to two dietary treatments and pigs in each group were arranged by control group (CK) diet or 8% maggot meal group (MMG) diet for 45 days respectively. Growth performance, indices of gut hormones and immunity in plasma were evaluated. Microbiota composition in faeces was determined using 16S rDNA Amplicon Sequencing. The results showed that dietary MMG did not affect gut hormones and immune proteins in the trial compared with CK group (p > .05). However, dietary MMG significantly increased average daily gain (ADG). The population of the Firmicutes in MMG treatment was increased, while the percentage of the Bacteroidetes was decreased (p < .05). In particular, the number of Clostridiales related to hydrolyzed sugar and protein were increased (p < .05). It can inhibit the growth of harmful intestinal bacteria, promote the proliferation of beneficial bacteria and effectively improve the ability of digestion and absorption of nutrients. In conclusion, a diet containing 8% MMG changed the proportion of intestinal micro-organisms in finishing pigs, especially the higher richness of Firmicutes, and promoted the fattening ability of pigs to a certain extent. These changes should benefit finishing pig production during fattening period.     

昆虫速激肽相关肽及其受体的研究进展

速激肽是具有多种生物学活性功能的神经多肽家族,该家族在进化过程中具有较高的保守性。昆虫速激肽相关肽与速激肽在序列结构上具有一定的相似性,也属于肽类神经递质,主要分布在昆虫的脑和肠组织中,并通过受体与配体之间的相互作用调节细胞内的一系列信号通路,从而产生多种生物学效应。本文重点介绍家蚕速激肽受体的发现以及通过对配体-受体互作的分析简述其信号转导机制的研究进展。     

Informal Nutrition Symposium: Dynamics of the Digestive System Introduction

The PSA Informal Nutrition Symposium of 2005 provided excellent lessons in many areas related to the dynamics of the digestive system. The following are brief comments about the 5 outstanding presentations.Doug R. Korver explored the similarities between the avian and mammalian gut immune functions [1]. It is of critical interest that activation of the immune system will divert nutrients from production functions.Guillermo Tellez emphasized the importance of understanding the complexity of the gut microflora [2]. Such an understanding could lead to effective management of microorganisms in the digestive system.Charles L. Hofacre reviewed the importance of certain ionophores in playing a beneficial role in competitive exclusion of some bacteria in the digestive system and reducing the risk of necrotic enteritis [3].Edwin T. Moran, Jr., addressed the interrelationships between the anatomy, microbes, and fiber with special emphasis on the comparisons between the small and large intestines [4]. Different strategies are used by the digestive system to manage nutrient absorption at the intestinal surfaces. Such strategies were explored comprehensively.Elizabeth A. Koutsos elaborated on the value of using new technologies in studying the bacterial communities rather than focusing on individual microorganisms [5]. Discovering and pinpointing interactions among the intestinal ecology, anatomy, microflora, and nutrition will ultimately help reach a meaningful understanding.     

饲粮纤维影响猪肠道健康的研究进展

肠道健康包括有效的营养物质吸收、稳定的肠道微生物群落及健全的免疫功能等多个方面。肠道的健康状况决定了动物的健康状况。肠道健康取决于饲粮、肠道黏膜和肠道微生物群落3个主要方面。饲粮纤维是由纤维素、半纤维素、果胶和木质素等组成的成分和结构复杂的混合物,具有改善肠道营养物质吸收、降低肠道环境p H、改变有益菌与潜在致病菌比例、优化肠道微生物群落组成及加强黏膜屏障作用等功能。来源不同和理化性质相异的饲粮纤维对肠道健康的影响及作用机理并不一致。本文就饲粮纤维的分类、理化性质及其对肠道健康影响的研究进展进行综述,以促进饲粮纤维在猪饲粮生产上的进一步广泛合理利用。     

Microbial diversity and structure in the gastrointestinal tracts of two stranded short-finned pilot whales (Globicephala macrorhynchus) and a pygmy sperm whale (Kogia breviceps)

Information on the gut microbiome composition of different mammals could provide novel insights into the evolution of mammals and succession of microbial communities in different hosts. However, there is limited information on the gut microbiome composition of marine mammals, especially cetaceans because of sampling constraints. In this study, we investigated the diversity and composition of microbial communities in the stomach, midgut, and hindgut of 2 stranded short-finned pilot whales (Globicephala macrorhynchus) and hindgut of a stranded pygmy sperm whale (Kogia breviceps) by using 16S rRNA gene amplicon sequencing technology. On the basis of the 50 most abundant operational taxonomic units, principal coordinate analysis, and non-metric multidimensional scaling analysis, we confirmed that the gut microbial communities of the 3 whales were different. Our results revealed that the gut microbiome of 1 stranded short-finned pilot whale GM16 was dominated by Firmicutes (mainly Clostridium) and Fusobacteria; whereas that of the other pilot whale GM19 was composed of Gammaproteobacteria and Bacteroidetes (mainly Vibrio and Bacteroides, respectively), probably caused by intestinal disease and antibiotic treatment. The gut microbiome of the pygmy sperm whale was dominated by Firmicutes and Bacteroidetes. Moreover, different gastrointestinal tract regions harbored different microbial community structures. To our knowledge, this is the first report of the gut microbiome of short-finned pilot whales, and our findings will expand our current knowledge on microbial diversity and composition in the gastrointestinal tract of cetaceans.     

微生物菌剂对伊犁绢蒿种子发芽特征的影响

为提高野外补播伊犁绢蒿(Seriphidium transiliense)幼苗的存活率,研究不同稀释倍数下(10、100、1 000、3 000、5 000、10 000倍)微生物菌剂对其发芽率、发芽势、根长、芽长及单株幼苗重的影响,并结合隶属函数法筛选最适宜的种子处理方式。结果表明,除复合芽孢杆菌抑制发芽率、发芽势外,适宜稀释倍数的生物菌剂均可提高伊犁绢蒿种子的发芽率、发芽势、根长、芽长及单株幼苗重。隶属函数综合评价认为,菌剂对该种子发芽及幼苗生长的促进效果由大到小依次为地衣芽孢杆菌、多粘类芽孢杆菌、复合芽孢杆菌、解淀粉芽孢杆菌、农用复合微生物菌、EM菌和放线菌。结合盆栽结果从微生物菌剂组合看,地衣芽孢杆菌稀释1 000倍、10倍、5 000倍及多粘类芽孢杆菌稀释1 000倍对伊犁绢蒿种子整体萌发生长提升效果较好,可作为补播前种子处理的首选措施。