益生菌防治糖尿病的研究进展

肠道菌群与糖尿病之间的关系正被研究者们所揭示.作为肠道中一类特殊的菌群,益生菌在延缓或治疗糖尿病方面有着独特的优势.本文从机理和优势的角度总结了益生菌防治糖尿病的研究进展,并对其发展趋势进行了展望.     

益生菌在犬猫上的应用研究进展

益生菌是一种定植于宿主肠道,能够调节肠道微生态平衡,提高宿主机体健康水平的活菌制剂。目前益生菌已被证实能够对动物起到多种有益的作用。随着宠物医疗行业的快速发展,犬猫的健康越来越受到主人的重视,益生菌被广泛添加到宠物食品以及营养补充剂中,通过维持肠道微生态的平衡达到预防肠道疾病或提高肠道免疫力的目的。对益生菌的定义、种类和作用机制,以及益生菌在犬猫上的应用研究进展进行综述,以期为犬猫益生菌制剂的开发以及益生菌在宠物医疗行业的应用提供参考。     

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。     

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。     

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。     

猪饲用抗生素替代物研究进展

饲粮中长期添加低剂量抗生素可引发细菌耐药性等生物安全问题,进而影响畜产品品质和人类健康,因此亟需寻找合适的抗生素替代物。本文总结了植物提取物、益生菌、有机酸和酶制剂等主要的猪饲用抗生素替代物的应用效果,并重点论述了饲用抗生素替代物对猪生长性能、肉品质、微生物区系、免疫机能和抗氧化能力等的作用机理,以期为猪新型饲用抗生素替代物的研发和应用提供参考。     

Effects of Bacillus subtilis CSL2 on the composition and functional diversity of the faecal microbiota of broiler chickens challenged with Salmonella Gallinarum

Background: The chicken gastrointestinal tract contains a diverse microbiota whose composition and structure play important roles in gut functionality. In this study, microbial shifts resulting from feed supplementation with Bacillus subtilis CSL2 were evaluated in broilers challenged and unchallenged with Salmonella Gallinarum. To analyse bacterial community composition and functionality, 454 GS-FLX pyrosequencing of 16 S r RNA gene amplicons was performed.Results: The Quantitative Insights into Microbial Ecology(QIIME) pipeline was used to analyse changes in the faecal microbiota over a 24-h period. A total of 718,204 sequences from broiler chickens were recorded and analysed. At the phylum level, Firmicutes, Bacteroidetes, and Proteobacteria were the predominant bacterial taxa. In Salmonellainfected chickens(SC), Bacteroidetes were more highly abundant compared to control(NC) and Bacillus-treated(BT)chickens. At the genus level, in the NC and BT groups, Lactobacil us was present at high abundance, and the abundance of Turicibacter, unclassified Enterobacteriaceae, and Bacteroides increased in SC broilers. Furthermore, taxon-independent analysis showed that the SC and BT groups were compositional y distinct at the end of the 24-h period. Further analysis of functional properties showed that B. subtilis CSL2 administration increased gut-associated energy supply mechanisms(i.e. carbohydrate transport and metabolism) to maintain a stable microbiota and protect gut integrity.Conclusions: This study demonstrated that S. Gallinarum infection and B. subtilis CSL2 supplementation in the diet of broiler chickens influenced the diversity, composition, and functional diversity of the faecal microbiota. Moreover, the findings offer significant insights to understand potential mechanisms of Salmonel a infection and the mode of action of probiotics in broiler chickens.     

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.     

益生菌对类风湿关节炎的改善作用研究进展

类风湿关节炎是一种威胁全球人类健康的自身免疫性疾病,肠道菌群的平衡与类风湿关节炎密切相关。由于益生菌在改善肠道菌群紊乱、恢复正常肠道菌群中发挥重要作用,因此给益生菌治疗类风湿关节炎提供了可能。本文综述类风湿关节炎病因、机制及患者肠道菌群的变化,总结近年来益生菌在治疗类风湿关节炎中的研究现状,为进一步临床试验和今后的应用提供依据。     

微生态制剂在提高畜禽免疫力中的作用机制

作为一种替代抗生素的新型绿色添加剂,微生态制剂在畜禽养殖中主要用于维持畜禽健康、促进动物生长、提高饲料利用率。文章从调控动物胃肠道内微生物菌群、刺激动物免疫器官发育、分泌代谢产物激活动物自身免疫反应、改善养殖场环境进而改善动物健康状况等方面对现有的微生态制剂免疫机制进行综述。     

Probiotics in pigs — modulation of their intestinal distribution and of their impact on health and performance

Two probiotics of different ecological origin, Enterococcus faecium NCIMB 10415 and Bacillus cereus var. toyoi, were chosen as model organisms. Feed for sows during gestation/lactation and for piglets pre-/postweaning was supplemented with either of these probiotics. To evaluate the effect of different starting points of E. faecium NCIMB 10415 initiations the probiotic was administered to piglets of sows, which have not received the probiotic, from birth onwards or just postweaning. Here we report the impact of these variants on probiotic distribution in the gut, on the gut microbiota, on diarrhea and on performance. Both probiotic strains were detected immediately after the start of the supplementation in feces of sows and piglets. The vertical transfer of both probiotic strains with sow feces to piglets could be demonstrated already before suckling piglets had access to the supplemented diets. Both probiotics were recovered from all intestinal segments of piglets. The dominant autochthonous colonic microbiota of young piglets as revealed by denaturing gradient gel electrophoresis was more similar within than between treatment groups (control vs. probiotic). Both probiotics reduced the incidence of postweaning diarrhea (p < 0.05). For the E. faecium probiotic the relative magnitude of this effect was largely independent of dietary probiotic concentration or starting time of supplementation. Significant overall influence on piglet performance was observed only with the B. cereus probiotic.     

益生菌调控肠道闭锁蛋白表达的机制

紧密连接是肠上皮细胞间的主要连接方式,参与维持上皮细胞极性与调节肠屏障的通透性。闭锁蛋白(OCLN)是紧密连接相关蛋白中最具代表性的蛋白之一,是形成紧密连接的基础结构。OCLN的功能主要包括栅栏功能和细胞旁屏障功能,研究发现其表达量降低时可引起肠黏膜屏障功能受损,后者是多种消化道疾病发生发展的一个重要过程。益生菌被认为是抗生素的重要替代物之一,其作用于宿主可产生多种有益作用。大量研究表明给予患者或者为疾病模型动物提供益生菌可有效改善肠黏膜屏障功能。本文就益生菌对肠道OCLN蛋白表达调控机制的研究作一综述,以期为OCLN相关研究和疾病的治疗策略提供理论参考。     

Current experimental models,assessment and dietary modulations of intestinal permeability in broiler chickens

Maintaining and optimising the intestinal barrier (IB) function in poultry has important implications for the health and performance of the birds. As a key aspect of the IB, intestinal permeability (IP) is mainly controlled by complex junctional proteins called tight junction proteins (TJ) that link enterocytes together. The disruption of TJ is associated with increased gut leakage with possible subsequent implications for bacterial translocation, intestinal inflammation, compromised health and performance of the birds. Despite considerable data being available for other species, research on IP in broiler chickens and in general avian species is still an understudied topic. This paper reviews the available literature with a specific focus on IP in broiler chickens with consideration given to practical factors affecting the IP, current assessment methods, markers and nutritional modulation of IP. Several experimental models to induce gut leakage are discussed including pathogens, rye-based diets, feed deprivation and stress-inducing agents such as exogenous glucocorticoids and heat stress. Although various markers including fluorescein isothiocyanate dextran, expression of TJ and bacterial translocation have been widely utilized to study IP, recent studies have identified a number of excreta biomarkers to evaluate intestinal integrity, in particular non-invasive IP. Although the research on various nutrients and feed additives to potentially modulate IP is still at an early stage, the most promising outcomes are anticipated for probiotics, prebiotics, amino acids and those feed ingredients, nutrients and additives with anti-inflammatory properties. Considerable research gaps are identified for the mechanistic mode of action of various nutrients to influence IP under different experimental models. The modulation of IP through various strategies (i.e. nutritional manipulation of diet) may be regarded as a new frontier for disease prevention and improving the health and performance of poultry particularly in an antibiotic-free production system.     

Effects of dietary supplementation with benzoic acid (VevoVitall®) on the zootechnical performance, the gastrointestinal microflora and the ileal digestibility of the young pig

The addition of organic acids to diet of young pigs has been shown to improve their zootechnical performance. The aim of these experiments was to evaluate the effects of dietary supplementation with BA (VevoVitall®) on the zootechnical performance (DWG and FCR), the gastrointestinal microflora of the weaner piglet and to determine the effects on the ileal digestibility. For the zootechnical and microbiological evaluations 124 28-day-old piglets were used. During 32 days half of them were fed a maize–soybean meal based diet and the other half this diet supplemented with 0.5% BA. At the end of the study the stomach and caecum contents were sampled from 12 animals of each group for microbiological determinations. For the ileal digestibility study 60-day-old ileo-rectal anastomosed piglets were used and fed alternatively the same diet supplemented or not with 0.5% BA. Digestibilities of total nitrogen (N), energy (E) and amino acids (AA) were evaluated.

The BA group had significantly higher DWG and FCR than that of the control group. BA reduced almost all the determined bacterial populations of the gastrointestinal tract of the piglet. The reductions were significant for gastric lactic acid bacteria and caecal E. coli. The ileal digestibility of E and AA was numerically improved and that of N significantly increased in the BA group.     

犬用益生菌研究进展

随着宠物饲养观念的改变,犬用益生菌的市场也在不断扩大。在犬的临床诊疗中,益生菌常用于调节肠道菌群、增强免疫力、提高幼犬生长性能、调节炎性反应、预防草酸钙结石和增强抗氧化性能等方面。就以上方面的应用进行阐述,分析犬用益生菌可能的作用机理和目前存在的问题,并探讨其未来发展前景和方向,以期为犬用益生菌的进一步合理开发和有效应用提供参考。     

Assessment of commercial probiotic bacterial contents and label accuracy

Probiotics are widely available for use in animals but quality control of veterinary probiotics has been shown to be poor. The objective of this study was to evaluate the labels and bacterial contents of commercial probiotics marketed for use in animals. Twenty-five probiotics were purchased, labels were scrutinized, and bacterial contents were enumerated. Twenty-one (84%) products listed specific microorganisms. Expected bacterial numbers were listed for 15 (60%) products. One or more organisms were misspelled on the labels of 7/22 (32%) of products that listed specific organisms. Viable growth ranged from 0 to 2×10(9) colony forming units (CFU)/g. Only 4/15 (27%) products that had specific claims of viable organisms met or exceeded their label claim. Only 2 of these also had an acceptable label, which properly described the contents. Deficiencies in veterinary probiotic quality remain. Veterinarians and owners should scrutinize commercial probiotics and demand evidence of quality control and efficacy.     

益生菌对肠道黏膜免疫的影响

益生菌作为一类以活菌为主的新型菌制剂,能在肠道内定殖,维护肠道菌群平衡,并刺激肠黏膜免疫组织,对肠道黏膜免疫有重要的影响。益生菌可直接作用于宿主的免疫系统,刺激胸腺、脾脏和法氏囊等免疫器官的发育,促进巨噬细胞活力或发挥佐剂作用,活化肠黏膜内相关淋巴组织,使免疫球蛋白A分泌增加,使免疫球蛋白A生物合成增加,提高消化道黏膜免疫功能。     

两种酶制剂与三种益生菌协同对种鸭生产性能的影响

本研究旨在探究酶和益生菌对不同周龄种鸭生产性能的影响。选取33周龄和70周龄樱桃谷肉种鸭各4棚,设置酶加益生菌制剂组(菌酶复合组)、酶制剂组、菌制剂组、对照组共4组。前三组按照500 g/t的剂量分别加入酶加益生菌制剂、酶制剂、菌制剂,对照组饲喂基础饲粮。饲喂周期46 d。统计各组种蛋的平均蛋重、可孵率、正品率、破蛋率、无精蛋率、孵化率。试验结果表明,1)蛋重:不同周龄菌酶复合组与酶剂组差异不显著(P<0.05),与菌剂组和对照组均有明显差异(P<0.05)。2)可孵率、无精蛋率:不同周龄菌酶复合组与酶剂组和菌剂组无显著差异(P>0.05),与对照组均有明显差异(P<0.05)。3)正品率:70周龄菌酶复合组与酶剂组无明显差异(P>0.05),与菌剂组和对照组均有明显差异(P<0.05);33周龄菌酶复合组与酶剂组、菌剂组和对照组均无明显差异(P>0.05)。4)破蛋率:不同周龄菌酶复合组与菌剂组无明显差异(P>0.05),与酶剂组和对照组均有明显差异(P<0.05)。5)无精蛋率:不同周龄菌酶复合组与酶剂组、菌剂组均无显著差异(P>0.05),与对照组差异显著(P<0.05)。6)孵化率:70周龄菌酶复合组与酶剂组、菌剂组均无显著差异(P>0.05),与对照组差异显著(P<0.05);33周龄菌酶复合组与酶剂组无显著差异(P>0.05),与菌剂组和对照组差异显著(P<0.05)。上述研究结果表明:酶与益生菌联合应用能够有效的延缓高周龄种鸭生产性能的衰退,同时还能够促进低周龄种鸭生产性能的升高。     

环境温度对动物肠道微生物菌群影响的研究进展

温度是一个重要的非生物环境变量,能够驱动动物谱系的适应轨迹和动物群落的组成。环境温度作为影响动物肠道微生物菌群变化的众多因素之一,能够影响肠道微生物菌群的组成及丰度,进而调控宿主生长、发育、繁殖、免疫等生物学过程及功能。动物肠道核心菌群的组成及其代谢产物在不同温度下存在显著差异,在单胃动物、反刍动物等中都有相应的报道。极端温度主要通过诱导肠道微生物菌群产生结构和功能上的差异,进而对宿主表型产生影响。目前,对于温度如何影响动物肠道菌群的了解仍非常有限。本文针对不同环境温度条件下,肠道微生物菌群结构和功能的差异及相关研究进行了总结及综述。探讨由环境温度引起的肠道微生物菌群与宿主适应机制之间的关系,包括对宿主产热机制、消化系统和免疫系统等其他方面的影响并开展研究,将为肠道微生物对宿主健康的调节提供参考和思路。     

饲用益生菌对动物肠道免疫调节的作用机理

益生菌即一类以活菌为主的新型饲料添加剂,其活菌能在动物肠道内定植,维护肠道菌群平衡,并刺激肠黏膜免疫系统,引起体液免疫和细胞免疫应答,从而增强机体抗病力.本文对益生菌的免疫刺激及其作用机理进行综述.