水产动物益生菌及其对肠道菌群影响的研究进展

随着水产动物肠道微生态学的发展,人们已逐步意识到益生菌对水产动物肠道发挥的重要作用,益生菌可通过调节肠道菌群平衡、改善肠道菌群组成等提高水产动物的免疫功能。本文综述了水产动物益生菌及其对肠道菌群的影响。     

肠道菌群与肠上皮细胞互作关系的研究进展

肠道菌群数量大、种类繁多,会对宿主产生各种各样的影响,包括营养代谢、免疫系统调节和抵御感染等,在维持肠道稳态平衡中起着重要作用。肠道上皮细胞是肠道防御系统的关键。肠道上皮是动物机体抵御微生物的第一道屏障,具有吸收和屏障功能,还是宿主与微生物群交流的主动传感器,而这样的功能是肠道菌群与肠上皮各类细胞间相互作用的结果。论文以肠道菌群与肠上皮细胞中的几类典型细胞之间的互作关系展开论述,旨在为如何通过各类细胞发挥的功能来协调肠道菌群的稳定,进而为预防或治疗某些由于肠道菌群失调而导致的疾病提供理论依据。     

犬猫肠道菌群特点与营养调控研究进展

肠道菌群逐渐被认为是与犬猫健康密切相关的代谢活性器官,其参与营养物质的消化吸收、机体代谢及免疫等多种生理功能,决定着犬猫整体健康状态。食物营养素作为犬猫肠道菌群的生长基质,在决定肠道微生物组成及代谢方面起着重要作用。宠物食品中除碳水化合物、蛋白质和脂肪等营养成分外,也包括越来越多的微生物靶向成分,如益生菌和益生元等,这些营养素亦能调控犬猫肠道菌群结构及微生物代谢产物的生成,以达到改善宠物整体健康的目的。为此,本文就犬猫肠道菌群特点、功能以及饮食营养素对犬猫肠道菌群的影响进行综述,旨在为营养调控肠道菌群,改善犬猫健康及促进功能性宠物食品发展提供理论依据。[关键词] 犬猫|肠道菌群|益生菌|益生元     

益生菌对猪肠道菌群的调控研究进展

<正>随着肠道微生态学的发展,人们逐渐认识到益生菌对于维持动物肠道菌群平衡发挥着重要作用。本文综述了猪肠道菌群的建立和分布、益生菌对肠道菌群的调控作用以及益生菌制剂的合理应用等问题,旨在为益生菌     

益生菌经肠道菌群调节肉鸡骨代谢的研究进展

在肉鸡饲养过程中,腿病作为一类常见的疾病,主要与骨骼的生长发育异常有关,这类疾病不仅有损肉鸡的动物福利,还会降低肉鸡的经济价值.目前,除了改善饲养管理、遗传育种和饲料营养等技术预防和治疗肉鸡腿病,还没有确切的药物治疗方法.因此,迫切需要寻找一种有效的干预策略来治疗肉鸡的腿部疾病.研究发现,益生菌不仅在改善禽类腹泻、脂肪...     

益生菌调节肠道菌群的研究现状

肠道菌群是由种类繁多的大量微生物组成的复杂的生态系统,与宿主的生长、发育、物质代谢和衰老等有密切关系。益生菌是一种能通过改善肠道微生态平衡而促进人体健康的微生物。本文综述了近年来益生菌调节肠道菌群研究的概况。     

肠道寄生虫与菌群互作关系研究进展

肠道菌群是动物机体的重要组成部分,与寄生虫和宿主的关系十分密切。寄生虫感染往往会对宿主产生不利影响,其致病作用与寄生虫种类、寄生部位及其与宿主的相互作用有关。寄生虫感染可导致肠道微生态的改变、失调和炎症性疾病;肠道菌群也影响寄生虫在宿主体内的定植、增殖和毒力。肠道寄生虫包括寄生蠕虫和原虫,近年来对肠道寄生虫与菌群相互作用研究发现,无论是原虫还是蠕虫感染均可导致肠道微生物组成和多样性的改变,对宿主产生致病作用,而蠕虫对炎症性肠病的潜在治疗作用一度颠覆了以往人们对于寄生虫的认知。肠道菌群可促进或抑制寄生虫对宿主的致病作用,且益生菌对肠道寄生虫感染有一定的预防或治疗作用。目前对寄生虫与菌群相互作用的研究仍然处于初期阶段,对其相互作用的机制尚不清楚。明确寄生虫与肠道菌群的相互影响及其作用机制,对深入理解寄生虫－肠道菌群－宿主的相互关系、研发有效的抗寄生虫微生态制剂具有重要意义。作者就近年来肠道蠕虫和原虫与菌群相互作用的研究进展进行了综述,并对该领域未来的研究方向进行展望,以期为预防和控制寄生虫病提供新的策略和理论依据。     

动物肠道菌群与病原微生物感染关系的研究进展

动物肠道内寄居着大量微生物,通常被称为共生菌群。它们对动物的生长、代谢和免疫状态至关重要,还与许多疾病的发生密切相关。病毒、细菌和寄生虫感染都会使机体的肠道菌群发生紊乱,表现在益生菌丰度减少而有害菌丰度增加。其机制包括引发宿主的炎症反应和抑制机体的免疫细胞两方面。同样肠道菌群也会调控病原菌的感染,如肠道菌群对不同的病毒会产生颉颃或促进作用,对细菌和寄生虫分别产生抑制和促进作用。肠道菌群抑制病原菌的机制包括与病原菌竞争代谢产物和诱导宿主的免疫反应。肠道菌群促进病毒感染的机制包括3点,分别为提高病毒的稳定性及其与靶细胞的黏附作用、抑制机体免疫系统和刺激靶细胞的增殖。肠道菌群促进寄生虫感染的可能机制包括降低Th2细胞因子(如IL-4和IL-13)并提高调节性T细胞的表达频率。肠道菌群、病原微生物和宿主不断相互作用,形成一个动态的平衡关系,并在感染过程中不断进化。作者主要综述了病毒、细菌和寄生虫感染对动物肠道菌群的组成和丰度的影响,动物肠道菌群如何影响病毒、细菌和寄生虫的感染进程并分析相关机制,以期了解疾病的发病机理,为疫苗佐剂的研发及制定更有效的预防和治疗策略提供新视角和理论依据。     

益生菌剂对仔猪肠道菌群的影响

为研究益生菌剂对仔猪肠道菌群的影响,选择60头7.5 kg左右的"杜洛克猪×长白猪×大白猪"原种猪,随机分成2组,每组3个重复,每个重复10头。将仔猪分为试验组和对照组,对照组饲喂基础日粮,试验组饲喂基础日粮+0.1%益生菌剂,检测各组仔猪生产性能及肠道菌群等。试验结果表明,益生菌制剂能显著降低仔猪腹泻率(P<0.05),促进仔猪的生长;大肠杆菌和肠球菌是仔猪肠道非常住菌群(过路菌),乳酸杆菌、双歧杆菌、产气荚膜梭菌为常住菌群;益生菌剂能极显著减少仔猪肠道的好氧菌(P<0.01),极显著增加仔猪肠道的厌氧菌、双歧杆菌和乳酸杆菌(P<0.01),显著降低仔猪肠道的产气荚膜梭菌(P<0.05)。因此,饲料中添加益生菌剂能有效改善仔猪肠道菌群。     

初雏接种益生菌对雏鸡肠道菌群的影响

本试验研究了使用竞争排斥类益生菌制剂(CE)对初生雏鸡肠道菌群的影响。试验一随机将180只刚出壳雏鸡分为两组,试验组在0d每只口服接种益生菌106CFU,而对照组则口服无菌生理盐水。通过选择性培养和DGGE带型分析,研究不同日龄雏鸡盲肠内容物中菌群结构的变化。结果表明:试验和对照组的细菌总数差异不显著,试验组的大肠杆菌数显著低于对照组(P<0.05),试验组的乳酸杆菌数高于对照组;肠球菌数低于对照组,但二者差异不显著。PCR-DGGE结果表明试验组的电泳条带明显多于对照组,而且两组肠道菌群按不同处理明显地聚类成两大分支,说明初雏接种益生菌可以影响后期的盲肠菌群结构。试验二的分组和0d处理同试验一,两组随后在1d均口服接种鼠伤寒沙门氏菌。通过检测沙门氏菌和耐药性大肠杆菌定植数量来比较益生菌对雏鸡的保护率。结果表明:在12d,对照组盲肠内沙门氏菌阳性率为46.15%,而试验组则未检出。同时,与对照组相比,试验组盲肠内耐30ppm卡那霉素和5ppm氨苄青霉素的大肠杆菌数量下降显著。以上结果显示,竞争排斥类益生菌制剂不仅可在雏鸡肠道内成功定植,而且可以显著降低肠道沙门氏菌的数量。     

Interplay between gut microbiota and antimicrobial peptides

The gut microbiota is comprised of a diverse array of microorganisms that interact with immune system and exert crucial roles for the health. Changes in the gut microbiota composition and functionality are associated with multiple diseases. As such, mobilizing a rapid and appropriate antimicrobial response depending on the nature of each stimulus is crucial for maintaining the balance between homeostasis and inflammation in the gut. Major players in this scenario are antimicrobial peptides (AMP), which belong to an ancient defense system found in all organisms and participate in a preservative co-evolution with a complex microbiome. Particularly increasing interactions between AMP and microbiota have been found in the gut. Here, we focus on the mechanisms by which AMP help to maintain a balanced microbiota and advancing our understanding of the circumstances of such balanced interactions between gut microbiota and host AMP. This review aims to provide a comprehensive overview on the interplay of diverse antimicrobial responses with enteric pathogens and the gut microbiota, which should have therapeutic implications for different intestinal disorders.     

A possible relationship between viral infection and chromosome damage in breeding boars

A cytogenetic analysis of peripheral blood lymphocytes was carried out on breeding boars (n = 5) on a farm where viral infections (porcine parvovirosis) had occurred. Several different types of chromosomal aberrations were observed including chromatid breaks (23.60 +/- 2.88%), exchanges (9.60 +/- 8.99%), and fragments (4.26 +/- 3.31%). In addition, 2.94 +/- 1.74% of cells in metaphase showed pulverization. Cells with multiple aberrations were seen in two of five boars. The chromosomal damage in the boars may have been induced by a genotoxic agent such as a viral infection, and may also be related to the reproductive impairment of the pigs.     

The germfree murine animal: an important animal model for research on the relationship between gut microbiota and the host

The genomic island 3 (GI-3) shared by Brucella melitensis and Brucella abortus contains 29 genes encoding mostly unknown proteins. Within this island, the open reading frames (ORFs) BAB1_0278 and BAB1_0263 are present, BAB1_0278 encodes a hypothetical protein of 64 amino acids sharing a domain with the GcrA superfamily, whereas the amino acid sequence of BAB1_0263 showed 42% identity with an iron regulated Lsr2 protein. We obtained one deletion mutant for each one of these ORFs present within the B. abortus GI-3 named BA-278 and BA-263, respectively. Both mutants were evaluated with respect to their ability to invade and replicate in nonprofessional and professional phagocytes (HeLa and J774.A1 cells) and their virulence in mice. Both mutants invaded efficiently HeLa and J774. A1 cells, however, 48-h post-infection the BA-278 mutant showed a lower intracellular persistence. The deletion of the ORF BAB1_0278, also affected the persistence of B. abortus in the spleens of mice, unlike to the deletion of the ORF BAB1_0263. These results allow us to conclude that BAB1_0278 ORF contributes to virulence of Brucella, since it is necessary to establish an optimal infectious process.     

Association between the body weight of growing pigs and the functional capacity of their gut microbiota

Gastrointestinal microbiota impact host's biological activities, including digestion of indigestible feed components, energy harvest, and immunity. In this study, fecal microbiota of high body weight (HW) and low body weight (LW) growing pigs at 103 days of age were compared. Principal coordinates analysis separated the HW and LW groups into two clusters, indicating their potential differences between microbial community composition. Although the abundances of two major phyla, Firmicutes and Bacteroidetes, did not significantly differ between the HW and LW groups, some genera showed significant differences. Among them, Peptococcus and Eubacterium exhibited strong positive correlations with body weight (BW) and average daily gain (ADG) (Rho > 0.40), whereas Treponema, Desulfovibrio, Parabacteroides, and Ruminococcaceae_unclassified exhibited strong negative correlations with BW and ADG (Rho < ?0.40). Based on these results, the structure of intestinal microbiota may affect growth traits in pigs through host–microbe interactions. Further in‐depth studies will provide insights into how best to reshape host–microbe interactions in pigs and other animals as well.     

Interactions between viral infection and immune mechanisms

Viruses differ from other infectious agents mainly in two respects: (a) they may be generated in the genome of normal cells and, in other instances, reinserted into the genome as proviruses, (b) they may participate in all pathologic processes that form the main subject of immune surveillance and immunity such as infectious diseases, tumourous growth, and, auto-aggressive processes.

Due to intracellular and cell modifying character of virus infection, the immune mechanisms are often unsuccessful in elimination of the agent from the vertebrate organism and may show disturbances contributing to development of a persistent viral disease. As exemplified by two forms of leprosy, intracellular bacteria may also cause ‘slow’ diseases. Their course, in analogy with viral slow diseases, seems to reflect the changed immunological potential of the infected host.     

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.     

鸭病毒性肝炎诊断技术的研究进展

本文综述了鸭肝炎病毒的诊断技术,包括常规的病毒分离技术、血清学诊断技术及分子生物学诊断技术,着重对目前广泛应用的血清学诊断技术如中和试验、琼脂扩散试验、凝集试验、荧光抗体技术、酶联免疫吸附试验和胶体金技术等进行了介绍,比较了各种方法的优缺点,并对鸭肝炎病毒诊断技术进行了展望。     

牦牛病毒性腹泻病研究进展

牦牛感染牛病毒性腹泻病毒(Bovine viral diarrhea virus,BVDV)后常发生胃肠炎等消化系统疾患和呼吸系统疾患、繁殖障碍,造成机体损伤,给牦牛产业发展造成一定影响。基于5"-UTR的差异将BVDV分为BVDV-I和BVDV-II两种基因型,牦牛源BVDV的主要基因型为BVDV-1型;根据BVDV对宿主细胞的致病性,分为致细胞病变型(Cy-topathogenic,CP)和非致细胞病变型(Non-cytopathogenic,NCP)两个生物型,牦牛源BVDV既有CP型又有NCP型,且这两种生物型能相互转化。牦牛生活的高原地区风、鸟类的迁徙等因素可能都会导致牦牛BVD传播范围广泛,牛群中大量的BVDV携带者和牦牛特殊而又复杂的生态系统导致了BVDV种间传播的巨大潜力,影响着牦牛产业的健康发展和养殖经济收益。针对本病在牦牛群中的感染流行等情况未发现相关详细的研究报道,笔者就牦牛BVD病原学、流行病学调查、实验室诊断、综合防治等方面研究进展情况进行整理,供同仁在研究和防控中参考借鉴。     

热应激蛋白与病毒免疫应答研究进展

热应激蛋白(Heat Shock Proteins,HSPs)是生命体处于应激状态时机体为维护蛋白质正常生理功能而产生的一类伴侣蛋白。1962年,Ritossa最早发现了热应激反应[1],随后,Tissiere在该反应中成功分离到由基因转录增强而形成的蛋白质并将其命名为热应激蛋白(又名热休克蛋白)[2]。由于热应激蛋白种类繁多,迄今为止尚没有具体的分类标准,所以根据其分子量大小和主要功能,可将热应激蛋白大致分为几种不同的家族.     

牛病毒性腹泻疫苗的研究进展

牛病毒性腹泻(bovine viral diarrhea,BVD)作为一种病毒性腹泻黏膜病,给养殖业造成了巨大的经济损失,应用疫苗来防控牛病毒性腹泻病毒(bovine viral diarrhea virus,BVDV)依然是重要的方法。直至目前,我国还没有成熟的BVDV疫苗,本研究主要综述了近几年来国外BVDV疫苗的研究进展,旨在为国内BVDV疫苗的研制及应用提供参考。