益生元与鸡肠道微生物的关系和研究进展

益生元是非消化饲料原料由特定的肠道微生物菌群代谢为宿主提供能量,并通过调节肠道微生物菌群防止病原体黏附宿主细胞来影响肠道健康。对鸡只肠道微生物菌群和益生元调节肠道微生物菌群和免疫功能的研究现状进行综述,以便我们更好地了解家禽肠道微生物菌群,对动物健康和生产能力的提高提供理论指导。     

辅助性T细胞17/调节性T细胞平衡调控炎症性肠病及其在动物生产上的应用

炎症性肠病(IBD)通常由易感基因、环境和免疫系统之间复杂的一系列相互作用引起,会造成肠道屏障机能紊乱。由白细胞分化抗原4阳性辅助T细胞(CD4+T)的2个子集辅助性T细胞17(Th17)和调节性T细胞(Treg)组成的平衡轴可以对IBD进行正负调节,Th17促进IBD,Treg抑制IBD。这种调控作用与多种信号传导通路有关。参考前人研究中利用各类饲料添加剂刺激Th17/Treg平衡及治疗IBD的报道,本文就Th17与Treg的分化、IBD的发病机理、Th17/Treg平衡相关信号通路以及基于Th17/Treg平衡开发饲料添加剂以调控IBD等方面进行综合阐述。     

驴乳对小鼠肠道菌群的影响

驴乳作为一种天然的食品资源,近年来已逐渐成为研究开发热点。采用驴乳复原乳干预抗生素致肠道紊乱小鼠模型,并用平板计数法和16S扩增子测序技术,探索驴乳对小鼠肠道菌群的影响。结果表明,驴乳可显著提升小鼠肠道菌群的丰度及益生功能菌比例,表现出了较好的益生与保健功能。     

芽孢杆菌的果寡糖制剂对断奶仔猪肠道菌群的影响

当前动物营养研究认为,无论是抗生素(an-tibiotics)、益生素(probiotics)还是益生元(prebi-otics)都会影响动物肠道微生物群落的组成。一般认为,抗生素对肠道微生物具有非选择性杀灭和清除作用,其促生长作用通过消除肠道微生物对动物生长的抑制作用而实现。益生素和益生元或者是两者协同使用的合生素(synbiotics)则是通过人工定向补充有益微生物或者有益微生物的增殖物质来调整和改善肠道微生态,从而有利于提高动物生产性能。     

日粮中添加黄芪多糖对坏死性肠炎肉鸡Th17/Treg平衡和肠道菌群的影响

文章旨在探究日粮添加黄芪多糖（APS）对感染坏死性肠炎（NE）肉鸡免疫功能和肠道菌群的影响。使用2×2因子排列,将240只AA肉鸡（1日龄）随机分配到两组添加不同水平APS的日粮（0或200 mg/kg）和两个疾病攻击组（对照组或感染坏死性肠炎攻击组）。结果显示,与对照组相比,第31天时,APS添加组体重显著增加420 g（P＜0.05）。在13～15 d APS组体重平均显著增加50 g（P＜0.05）。与对照组相比,在第25～31天,补充APS可以显著增加平均采食量42 g,此外,日粮添加APS减轻了NE对生长性能的负面影响,并且显著增加了13～25 d及25～31 d的饲料转化率。膳食APS补充剂显著降低了肉鸡25日龄时血清中4%的Th17细胞比例、Th17/Treg比列及31日龄肉鸡盲肠中产气荚膜梭菌的数量。总之,APS可能通过调节肠道免疫、Th17/Treg平衡及肠道微生物群来减轻NE对肉鸡的影响。 [关键词]坏死性肠炎|黄芪多糖|Th17/Treg|肠道菌群|肉鸡     

基于16S rRNA测序分析PRRSV感染仔猪肺和肠道中微生物菌群的变化

本试验旨在探究猪繁殖与呼吸综合征病毒(porcine reproductive and respiratory syndrome virus, PRRSV)感染对仔猪肺、肠道中的菌群影响以及肺和肠道的组织学变化。试验选取35日龄断奶健康仔猪14头，适应性饲养7 d,随机分为感染组(n=7)和对照组(n=7),感染组仔猪接种2 mL 1×10⁵ TCID₅₀·mL^-1PRRSV-JTS毒株病毒液，对照组仔猪接种2 mL DMEM培养基。感染组3头仔猪分别于10、12和19 d死亡，将存活的感染组与对照组仔猪于21 d后处死，并取肺、不同肠段组织样品以及肠道内容物。采用免疫组化染色和HE染色观察肺和肠道组织病理学变化，并基于16S rRNA基因的高通量测序分析仔猪肺和各肠段菌群结构。结果表明，感染组仔猪肺部和肠道均有病毒分布；与对照组仔猪相比，感染组仔猪肺部和肠道均存在明显的炎症反应。微生物组成结构及多样性分析显示，感染组仔猪Chao1、ACE指数在肺中上升，在仔猪各肠段中下降，Shannon、Simpon指数在肺中升高，在...     

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     

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。     

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。     

家禽胚蛋注射技术的应用研究(综述)——益生菌和益生元篇

益生菌可以是一种活菌制剂,也可以是细菌的代谢产物,它可以通过改变或重建动物肠道微生物菌群的组成来提高宿主的健康水平。益生元是植物中不能被宿主(动物)体内的酶分解的非淀粉多糖,能通过选择性刺激动物肠道微生物菌群的生长与活性对宿主产生有益的影响,从而改善宿主的健康水平。益生菌和益生元已经在畜牧生产中得到广泛的应用,一般经口补给,而胚胎供应或将成为给家禽添加益生菌或益生元的新途径,扩展其在动物保健方面的新功能。     

Effect of rifaximin on gut-lung axis in mice infected with influenza A virus

Gut-lung axis injury is a common finding in patients with respiratory diseases as well as in animal model of influenza virus infection. Influenza virus damages the intestinal microecology while affecting the lungs. Rifaximin, a non-absorbable derivative of rifamycin, is an effective antibiotic that acts by inhibiting bacterial RNA synthesis. This study aimed to determine whether rifaximin-perturbation of the intestinal microbiome leads to protective effects against influenza infection, via the gut-lung axis. Our results showed that influenza virus infection caused inflammation of and damage to the lungs. The expression of tight junction proteins in the lung and colon of H1N1 infected mice decreased significantly, attesting that the barrier structure of the lung and colon was damaged. Due to this perturbation in the gut-lung axis, the intestinal microbiota became imbalanced as Escherichia coli bacteria replicated opportunistically, causing intestinal injury. When influenza infection was treated with rifamixin, qPCR results from the gut showed significant increases in Lactobacillus and Bifidobacterium populations, while Escherichia coli populations markedly decreased. Furthermore, pathology sections and western blotting results illustrated that rifaximin treatment strengthened the physical barriers of the lung-gut axis through increased expression of tight junction protein in the colon and lungs. These results indicated that rifaximin ameliorated lung and intestine injury induced by influenza virus infection. The mechanisms identified were the regulation of gut flora balance and intestinal and lung permeability, which might be related to the regulation of the gut-lung axis. Rifaximin might be useful as a co-treatment drug for the prevention of influenza virus infection.     

绵羊痒螨巨噬细胞迁移抑制因子重组蛋白对兔外周血单个核细胞Th1/Th2型和Th17/Treg型特征因子表达的影响

为了初步探讨绵羊痒螨巨噬细胞迁移抑制因子（PoMIF）对健康新西兰兔外周血单个核细胞（PBMC）中Th1/Th2和Th17/Treg细胞平衡的变化。采用RT-PCR从绵羊痒螨总RNA中扩增得到MIF全长基因，经原核表达、纯化重组PoMIF（rPoMIF）蛋白，并分析其氧化还原酶和互变异构酶活性。筛选与健康新西兰兔PBMC孵育的最佳rPoMIF浓度，且用最佳浓度rPoMIF（0.2 μg·mL^-1）与PBMC共同孵育0、1、6、12、24、36 h后收集细胞，用荧光定量PCR检测其Th1/Th2/Th17/Treg细胞相对应的特征性转录因子T-bet/GATA-3/RORc/Foxp3和特征性细胞因子IFN-γ/IL-4/IL-17A/IL-10 mRNA表达变化。结果表明：PoMIF全长363 bp，rPoMIF大小为32 ku（含pET32a标签蛋白19 ku），且具有互变异构酶活性；rPoMIF刺激后PBMC中Th1细胞的T-bet和IFN-γ先下降后上升，Th2细胞的GATA-3和IL-4均呈下降趋势，且T-bet/GATA-3和IFN-γ/IL-4比值在12、24和36 h均升高；Th17细胞的RORc和IL-17A在各时间点下降，而Treg细胞的Foxp3和IL-10在各时间点升高，且RORc/Foxp3和IL-17A/IL-10比值在各时间点均变低。rPoMIF可造成家兔外周血单个核细胞的Th1/Th2和Th17/Treg平衡分别向Th1和Treg偏移。     

流感病毒受体在三种动物气管和肺脏分布的组织化学检测

利用凝集素组织化学染色的方法,对岭南黄鸡、番鸭和BALB/C小鼠的气管和肺脏进行了流感病毒受体分布的检测。结果表明:在岭南黄鸡、番鸭和小鼠的气管粘膜层、粘膜下层、肺脏的细支气管和肺泡上皮细胞均有禽流感病毒受体的分布。番鸭和小鼠气管和肺脏的人流感病毒受体的分布范围和细胞类型与禽流感病毒受体的分布稍有差异,岭南黄鸡气管和肺脏未检测到人流感病毒受体的分布。研究结果为探讨流感病毒的感染机制和宿主特异性的差异提供了基础数据。     

Plasmacytoid dendritic cell depletion leads to an enhanced mononuclear phagocyte response in lungs of mice with lethal influenza virus infection

Plasmacytoid dendritic cells (pDCs) have been implicated both in the control and pathogenesis of influenza virus infection. We demonstrate that pDC depletion has marked effects on the response of mononuclear phagocytes, including conventional DCs (cDCs) and macrophages, to lethal influenza virus infection. Infection of mice lacking pDCs through antibody-mediated depletion resulted in substantially increased accumulation of mononuclear phagocytes and their progenitors in lungs compared to non-treated controls. pDC ablation resulted in a 5- to 35-fold enhancement of intracellular TNF-α and IL-6 production from inflammatory cDCs and exudate macrophages. Purified pulmonary cDCs and macrophages cultured from pDC-depleted mice produced significantly elevated levels of pro-inflammatory cytokines and chemokines compared to pDC-intact counterparts. Elimination of pDCs resulted in decreased lung IFN-α production and an immediate and transient reduction in lung virus burden but did not impact disease outcome. These data reveal a suppressive effect of pDCs on the inflammatory response to influenza virus infection in the lung.     

Production and immunogenicity of chimeric virus-like particles containing the spike glycoprotein of infectious bronchitis virus

Infectious bronchitis virus (IBV) poses a severe threat to the poultry industry and causes heavy economic losses worldwide. Vaccination is the most effective method of preventing infection and controlling the spread of IBV, but currently available inactivated and attenuated virus vaccines have some disadvantages. We developed a chimeric virus-like particle (VLP)-based candidate vaccine for IBV protection. The chimeric VLP was composed of matrix 1 protein from avian influenza H5N1 virus and a fusion protein neuraminidase (NA)/spike 1 (S1) that was generated by fusing IBV S1 protein to the cytoplasmic and transmembrane domains of NA protein of avian influenza H5N1 virus. The chimeric VLPs elicited significantly higher S1-specific antibody responses in intramuscularly immunized mice and chickens than inactivated IBV viruses. Furthermore, the chimeric VLPs induced significantly higher neutralization antibody levels than inactivated H120 virus in SPF chickens. Finally, the chimeric VLPs induced significantly higher IL-4 production in mice. These results demonstrate that chimeric VLPs have the potential for use in vaccines against IBV infection.     

Gut microbiome colonization and development in neonatal ruminants: Strategies,prospects, and opportunities

Colonization and development of the gut microbiome is a crucial consideration for optimizing the health and performance of livestock animals. This is mainly attributed to the fact that dietary and management practices greatly influence the gut microbiota, subsequently leading to changes in nutrient utilization and immune response. A favorable microbiome can be implanted through dietary or management interventions of livestock animals, especially during early life. In this review, we explore all the possible factors (for example gestation, colostrum, and milk feeding, drinking water, starter feed, inoculation from healthy animals, prebiotics/probiotics, weaning time, essential oil and transgenesis), which can influence rumen microbiome colonization and development. We discuss the advantages and disadvantages of potential strategies used to manipulate gut development and microbial colonization to improve the production and health of newborn calves at an early age when they are most susceptible to enteric disease. Moreover, we provide insights into possible interventions and their potential effects on rumen development and microbiota establishment. Prospects of latest techniques like transgenesis and host genetics have also been discussed regarding their potential role in modulation of rumen microbiome and subsequent effects on gut development and performance in neonatal ruminants.     

Different infection routes of avian influenza A (H5N1) virus in mice

The continuing outbreaks of avian influenza A H5N1 virus infection in Asia and Africa have caused worldwide concern because of the high mortality rates in poultry, suggesting its potential to become a pandemic influenza virus in humans. The transmission route of the virus among either the same species or different species is not yet clear. Broilers and BABL/c mice were inoculated with the H5N1 strain of influenza A virus isolated from birds. The animals were inoculated with 0.1 mL 10^6.83 TCID₅₀ of H5N1 virus oronasally, intraperitoneally and using eye drops. The viruses were examined by virological and pathological assays. In addition, to detect horizontal transmission, in each group, healthy chicks and mice were mixed with those infected. Viruses were detected in homogenates of the heart, liver, spleen, kidney and blood of the infected mice and chickens. Virus antigen was not detected in the spleen, kidney or gastrointestinal tract, but detected by Plaque Forming Unit (PFU) assay in the brain, liver and lung without degenerative change in these organs (in the group inoculated using eye drops. The detection results for mice inoculated using eye drops suggest that this virus might have a different tissue tropism from other influenza viruses mainly restricted to the respiratory tract in mice. All chicken samples tested positive for the virus, regardless of the method of inoculation. Avian influenza A H5N1 viruses are highly pathogenic to chickens, but its virulence in other animals is not yet known. To sum up, the results suggest that the virus replicates not only in different animal species but also through different routes of infection. In addition, the virus was detection not only in the respiratory tract but also in multiple extra‐respiratory tissues. This study demonstrates that H5N1 virus infection in mice can cause systemic disease and spread through potentially novel routes within and between mammalian hosts.     

Piglet gut microbial shifts early in life:causes and effects

The gut microbiome has long been known to play fundamentally important roles in the animal health and the well-being of its host. As such, the establishment and maintenance of a beneficial gut microbiota early in life is crucial in pigs, since early gut colonizers are pivotal in the establishment of permanent microbial community structures affecting the health and growth performance of pigs later in life. Emphasizing this importance of early gut colonizers, it is critical to understand the factors impacting the establishment of the piglet gut microbiome at weaning. Factors include, among others, diet, in-feed antibiotics, probiotics and prebiotic administration. The impact of these factors on establishment of the gut microbiome of piglets at weaning includes effects on piglet gut microbial diversity, structure, and succession. In this review, we thoroughly reviewed the most recent findings on the piglet gut microbiome shifts as influenced by weaning, and how these microbiome changes brought about by various factors that have been shown to affect the development of microbiota in piglets. This review will provide a general overview of recent studies that can help to facilitate the design of new strategies to modulate the gut microbiome in order to enhance gastrointestinal health, growth performance and well-being of piglets.     

Effect of vitamin E supplementation on lipid peroxidation in blood and lung of influenza virus infected mice

The influenza virus infection (A/Aichi/2/68) was associated with development of oxidative stress in lung and blood of mice, accompanied by an increase in levels of lipid peroxidation products (conjugated dienes and total malondialdehyde) and a decrease in endogenous amounts of natural antioxidant vitamin E. These effects were most pronounced on the 5th day after virus inoculation, in comparison with those on the 7th. Supplementation of mice with exogenous vitamin E before virus inoculation lead to lung and blood protection against lipid peroxidation. A marked decrease in lipid peroxidation products and an increase in vitamin E content was established in blood and lung on the 5th and 7th day after virus inoculation. The stabilizing effect of vitamin E is dose-dependent in blood and dose-independent in lung, and was most pronounced on the 5th day after virus inoculation in comparison with the 7th day.