益生菌健康功能的研究进展

益生菌是活的微生物,当摄入足够数量时,对宿主起有益健康的作用。益生菌的健康作用逐步被科学验证,包括调节肠道菌群、抑制有害细菌、消炎、抗过敏、提高机体免疫力等,但益生菌发挥健康作用的机理却尚未定论。目前,普遍认为益生菌发挥健康作用可能有3种途径:调节肠道微生态环境、调节机体免疫、改善定殖抗性。本文重点针对益生菌的特征、选择标准、健康作用机制进行了综述。     

益生菌对硬骨鱼肠道黏膜免疫影响的研究进展

益生菌在健康硬骨鱼肠道中不仅起到抑制致病微生物的作用,而且更重要的是,益生菌能够刺激和增强肠道黏膜免疫系统,在肠道免疫中起重要作用。近年来,硬骨鱼黏膜免疫因其多样性及其不明确的定义,已成为热门的研究课题。硬骨鱼与水生环境直接接触,使肠道黏膜表面易受各种病原体的侵袭。免疫调节是硬骨鱼中有效的预防性措施,而益生菌能够提高肠道黏膜表面固有的免疫活性细胞和因子,对病原体起颉颃作用。益生菌主要通过口服方式进入鱼体,而肠道作为其主要靶器官,对鱼体产生特异性免疫应答。因此,关于益生菌影响肠道黏膜免疫系统的研究值得关注。相比于哺乳动物,硬骨鱼具有更加弥散的肠淋巴系统。局部免疫应答所必需的免疫细胞大量存在于肠道黏膜中,并且可以在免疫后的鱼体肠道中监测到局部免疫应答。文章综述了近年来硬骨鱼肠道黏膜免疫系统以及益生菌对硬骨鱼肠道黏膜免疫的影响,并对鱼类益生菌的进一步研究进行了展望,以期为后续研究益生菌与硬骨鱼之间相互作用提供参考。     

乳酸菌对生猪健康和生产性能的影响

病原体对抗生素的耐药性不断增强,以及动物源性食品中抗生素残留所带来的食品安全问题引起越来越多的关注。乳酸菌是一种安全、优质、高效的益生菌,可调节肠道环境,抑制或杀死胃肠道病原体,改善肠道微生物平衡,调节肠粘膜免疫力,保持肠屏障功能,有利于猪的健康,提供了抗生素策略的潜在替代方案。本文就饲料中添加乳酸菌作为益生菌对新生仔猪、断奶仔猪、生长育肥猪和母猪的作用进行综述,以期为进一步提高猪的生产性能和健康养殖提供参考,不断提高猪的福利和养殖水平。     

益生菌对肉鸡肠黏膜免疫屏障的影响

肉鸡肠道疾病严重影响着养鸡业的发展,利用益生菌防治肉鸡的肠道疾病已成为当今的研究热点。本文综述了益生菌的特点、肠黏膜免疫屏障、益生菌对肉鸡肠黏膜免疫屏障的作用(调节肠道内微生物的平衡、预防和治疗肠道炎症、增强肠道的免疫屏障),旨在阐明益生菌在肉鸡肠黏膜免疫屏障中的研究进展,为规模化养殖场合理使用益生菌提供理论依据。     

膳食营养素及饲料添加剂对猪肠道微生物群的影响研究进展

肠道微生物群有助于宿主肠道发挥多种生理功能,对改善猪的肠道健康、提高猪的生产性能具有重要作用。肠道微生物具有很强的可塑性,易受饮食、抗生素的摄入、病原体感染、宿主状况、外界环境等因素的影响。饮食的变化是影响肠道微生物群的主要因素。很多营养素和饲料添加剂具有调控猪肠道微生物的结构组成、促进肠道健康的作用。调节日粮营养素水平、补充饲料添加剂是猪生产中常用干预肠道微生物方法之一。文章综述膳食营养素和饲料添加剂（益生菌、益生元、酶制剂和植物生物素等）对猪肠道微生物群的影响,为其在猪生产中的应用提供参考。     

动物肠道黏膜抗菌肽维持微生物区系平衡机制探讨

<正>肠道微生物作为宿主的共生生物,能改善消化、吸收、合成维生素以及抑制病原菌的生长。同时宿主通过控制肠道微生物数量、组成及分布来维持肠道微生物的动态平衡。在此过程中,与微生物菌群相互作用的肠上皮细胞发挥了极其重要的作用。宿主肠道免疫防御系统产生的一类对抗外源性病原体致病作用的防御性肽类活性物质,称为抗菌肽。在肠道内最有代表性的抗菌肽是防御素、C型凝集素、核糖核酸酶和S100蛋白,在调节肠道微生     

Toll样受体及其对肠黏膜免疫的调节作用

Toll样受体(TLRs)是近年来备受关注的一种模式识别受体,在脊椎与非脊椎动物中具有病原体传感器的功能。TLRs对体内外特异性配体的识别是启动先天免疫的基础,并迅速增加对抗入侵病原体的保护性反应,最终激活适应性免疫。TLRs在肠道免疫对病原菌与益生菌的区分过程中发挥重要作用,同时TLRs可调控动物肠道上皮分泌抗菌肽杀灭病原菌,对肠道健康具有积极的作用。本文介绍了TLRs的种类、配体及相应的信号通路,探讨TLRs在肠道免疫调节中的关键作用。     

益生菌维护肠道健康及抗病毒作用研究进展

动物肠道存在复杂的微生物群落,适宜的微环境有利于多种肠道微生物的定植生长。肠道健康是保证动物机体健康的基础,也是当前国内外学者所关注的热点问题。益生菌是对肠道健康有益的微生物,在改善动物肠道健康领域具有极大的潜力。益生菌对病原微生物侵袭有一定的抑制作用,对部分病毒也具有一定的预防及清除作用,但不同菌株作用效果存在较大差异。作者首先将益生菌对肠道健康的保护概括为益生菌抑制病原菌入侵和定植、改善肠道屏障功能、维持肠道健康菌群、提高机体免疫力4种方式,并探讨了不同菌株的作用方式;其次简述了益生菌抗肠道病毒的作用机制,其中,益生菌通过间接方式调节机体免疫是其抗病毒的主要方式;最后讨论了近年来益生菌在轮状病毒、流行性腹泻病毒和传染性胃肠炎病毒中应用的研究进展,并对益生菌的发展前景进行了展望,以期为益生菌在改善动物肠道健康的研究及产品的开发方面提供一定的参考依据。     

短链脂肪酸介导的宿主肠道免疫调控机制

肠道是营养素、微生物群和宿主进行免疫反应的共享场所。肠道稳态失衡、免疫功能失调、环境因素等都可能引发疾病,肠道微生物群是控制机体健康肠道内环境平衡的一个重要因素。短链脂肪酸(SCFAs)主要由细菌发酵产生,是肠道微生物群及宿主肠上皮细胞(IECs)的重要能量来源,能够维持肠道酸碱平衡,抑制有害病原菌生长,调节宿主肠道免疫,降低炎症反应。SCFAs不仅在共生细菌聚居的肠道内起局部作用,而且还影响肠道免疫细胞,调节免疫反应。本文主要概述了SCFAs通过G蛋白偶联受体(GPCRs)激活途径、组蛋白脱乙酰化酶(HDAC)抑制作用改变代谢状态,并将代谢途径与表观遗传修饰联系起来引起宿主免疫应答,降低肠道炎症反应并增强肠道屏障功能。     

肠道微生物在反刍动物健康生产中的作用研究进展

近年来,随着各界对微生物功能的关注,人们对肠道微生物的研究也日益增多。在反刍动物的肠道中存在着大量的微生物,它们对宿主的营养代谢、免疫功能等起到了十分重要的作用,是影响机体健康的关键因素之一。肠道微生物受反刍动物的饲粮组成、年龄、基因型等因素的影响,而饲粮组成是影响肠道微生物最主要的因素,若饲粮改变,其中的粗纤维、蛋白质、碳水化合物等营养素均发生改变,肠道微生物也随之发生改变。反刍动物体内存在的有益微生物(如瘤胃球菌、藤黄微球菌、牛肠球菌等)对动物机体有积极的作用,而一些有害菌(如梭菌、苏黎世杆菌等)会破坏反刍动物体内环境的稳态,使机体免疫力、抗病力下降,容易产生疾病,严重影响反刍动物的健康。此外,除了肠道微生物会影响反刍动物机体健康外,益生菌和营养素也对反刍动物机体健康起到调控作用,而一般的措施都是在反刍动物饲粮中添加有益益生菌或营养素饲粮,这样既能补充日常的营养水平,也能防止有害微生物的增生,从而保障反刍动物机体的健康。作者综述了影响反刍动物肠道微生物的因素,以及益生菌和营养素对反刍动物健康生产的作用,旨在为合理调控反刍动物肠道微生物区系及为其健康发展提供理论参考,进而促进畜牧业的...     

Advances in Modulation of Intestinal Innate Defense Responses by Probiotic Bacteria

Probiotics are a kind of living microorganism which can be administered in feed and confer numerous health benefits to animals. Probiotics play a key role in maintaining the microbial balance of gastrointestinal, immunomodulation and pathogen defense, specific probiotics show certain degree of potential to reinforce the integrity of intestinal epithelium and regulate some immune components. The mechanism of probiotic action is an area of interest. Among all possible routes of modulation by probiotics of intestinal mediated defense responses, modulations of intestinal barrier function, innate and adaptive mucosal immune responses as well as signaling pathways are considered to play an important role in the intestinal defense responses against pathogenic bacteria. This review summarizes how probiotic bacteria interact with goblet cell-derived mucins, trefoil factors (TFFs),defensins, Toll-like receptors (TLRs), secretory immunoglobulin A (sIgA), heat shock proteins (HSPs) and P-glycoproteins (P-gp) in the gut to regulate the intestinal innate defense responses,which is regarded as the scientific basis for the future detailed study of benefits of probiotics towards the health of intestine and also dietary intervention against intestinal exposure to pathogens.     

Health-beneficial effects of probiotics: Its mode of action

It is now widely recognized that probiotics have health-beneficial effects on humans and animals. Probiotics should survive in the intestinal tract to exert beneficial effects on the host's health. To keep a sufficient level of probiotic bacteria in the gastrointestinal tract, a shorter interval between doses may be required. Although adherence to the intestinal epithelial cell and mucus is not a universal property of probiotics, high ability to adhere to the intestinal surface might strongly interfere with infection of pathogenic bacteria and regulate the immune system. The administration of probiotic Lactobacillus stimulated indigenous Lactobacilli and the production of short-chain fatty acids. This alteration of the intestinal environment should contribute to maintain the host's health. The immunomodulatory effects of probiotics are related to important parts of their beneficial effects. Probiotics may modulate the intestinal immune response through the stimulation of certain cytokine and IgA secretion in intestinal mucosa. The health-beneficial effects, in particular the immunomodulation effect, of probiotics depend on the strain used. Differences in indigenous intestinal microflora significantly alter the magnitude of the effects of a probiotic. Specific probiotic strains suitable for each animal species and their life stage as well as each individual should be found.     

益生菌在家禽饲料中应用的研究进展

益生菌主要通过提高饲料营养的消化利用、提高动物免疫调节能力为宿主动物胃肠道(GIT)健康提供益生作用。益生菌通过提高肠绒毛高度、改善黏膜结构来帮助营养成分的消化吸收、增强上皮细胞紧密连接的调节功能、防御病原菌、维持细胞稳态。益生菌对于热应激引起的环境挑战,也有很好的调节功能。     

The impact of probiotics on gut health via alternation of immune status of monogastric animals

The intestinal immune system is affected by various factors during its development, such as maternal antibodies, host genes, intestinal microbial composition and activity, and various stresses (such as weaning stress). Intestinal microbes may have an important impact on the development of the host immune system. Appropriate interventions such as probiotics may have a positive effect on intestinal immunity by regulating the composition and activity of intestinal microbes. Moreover, probiotics participate in the regulation of host health in many ways; for instance, by improving digestion and the absorption of nutrients, immune response, increasing the content of intestinal-beneficial microorganisms, and inhibiting intestinal-pathogenic bacteria, and they participate in regulating intestinal diseases in various ways. Probiotics are widely used as additives in livestock and the poultry industry and bring health benefits to hosts by improving intestinal microbes and growth performance, which provides more choices for promoting strong and efficient productivity.     

益生菌调节肠道菌群及免疫调节作用机理

益生菌是指改善宿主微生态平衡而发挥有益作用,达到提高宿主健康水平和健康状态的活菌制剂及其代谢产物。本文以乳酸菌、双歧杆菌和芽孢杆菌等几种常见的食用或饲用益生菌为对象,论述其调节肠道菌群和免疫调节作用的机理。     

Development of molecular immunoassay system for probiotics via toll-like receptors based on food immunology

Recent interest has focused on the importance of intestinal immunity for the host defense, but to date, not much is known about the underlying mechanisms. The toll‐like receptor (TLR) family plays an important role in host defense through recognizing bacterial pathogen‐associated molecular patterns. Our recent research on the physiological function of food products has investigated the immunoregulatory effects of probiotic lactic acid bacteria (LAB) via TLR. Studies of swine, which often substitute for a human model, have demonstrated intestinal immunoregulation by the probiotic LAB mediated by TLR in the gut. On the basis of our study, efforts have also been made to develop a molecular immunoassay system for probiotic LAB and find novel immunostimulatory DNA sequences from probiotics and high potential immunobiotic LAB strains via TLR signaling. These findings may provide important clues at the molecular level on TLR signal transduction pathways and recognition mechanisms for the ligands. They also provide impetus to further delineate the activation mechanism of the innate immune response. In addition to identifying immunoregulatory factor immunogenics from LAB, a better understanding of intestinal immune regulation through cytokine networks holds out promise for basic food immunology research and the development of immunobiotic foods to prevent specific diseases.     

Study and use of the probiotic Lactobacillus reuteri in pigs:a review

Probiotics are living microorganisms that provide a wide variety of health benefits to the host when ingested in adequate amounts.The bacterial strains most frequently used as probiotic agents are lactic acid bacteria,such as Lactobacillus reuteri,which is one of the few endogenous Lactobacillus species found in the gastrointestinal tract of vertebrates,including humans,rats,pigs and chickens.L reuteri is one of the most well documented probiotic species and has been widely utilized as a probiotic in humans and animals for many years.Initially,L reuteri was used in humans to reduce the incidence and the severity of diarrhea,prevent colic and necrotic enterocolitis,and maintain a functional mucosal barrier.As interest in alternatives to in-feed antibiotics has grown in recent years,some evidence has emerged that probiotics may promote growth,improve the efficiency of feed utilization,prevent diarrhea,and regulate the immune system in pigs.In this review,the characteristics of L reuteri are described,in order to update the evidence on the efficacy of using L.reuteri in pigs.     

益生菌在恢复家兔肠道菌群平衡和解决腹泻中的作用

益生菌是一类有益于宿主健康的活性微生物,可以通过调节家兔肠道菌群的平衡和增强肠道屏障功能来发挥作用,能够抑制有害菌的生长,提高消化道内营养物质的吸收利用,增强免疫系统的功能,从而维持肠道健康。本文从益生菌对家兔肠道菌群的影响,益生菌治疗机制的探索等方面探讨益生菌在恢复家兔肠道菌群平衡和解决腹泻中的作用,分析了当前研究的局限性和未来研究方向,有助于推动益生菌在家兔腹泻治疗中的临床应用,为家兔肠道健康提供更全面的保障。     

益生菌兼或益生元对牛肠道菌群调节作用研究进展

益生菌/益生元具有调节胃肠(GI)菌群平衡及活动的能力,能够显著地影响家畜肠道内菌群的结构和活动,使有益菌(主要是乳酸菌)占有生态位,成为优势菌群,抑制霉菌生长和霉菌毒素的产生。饲喂益生菌后,牛肠道中的菌群呈现多样性,群落的复杂程度增高,牛肠道菌群的微生态稳定性增强。低聚麦芽糖、低聚半乳糖等益生元则能不同程度的被有益菌分解利用,作为有益菌的生长促进剂,发挥其益生作用。目前,益生菌/益生元已被广泛应用于食品、医药保健和饲料等各个领域。随着对其深入的了解和成熟的市场或产业化发展,益生菌/益生元的应用前景很好。