微生物与仔猪肠道脂质代谢-免疫应答网络互作研究进展北大核心CSCD

仔猪阶段对于整个生猪养殖过程十分关键,然而仔猪肠道免疫系统发育还未完善,肠道微生物区系尚不稳定,易发生疾病。猪饲粮脂肪酸可以调节肠道脂质代谢、增强黏膜屏障和免疫功能以及改善肠道微生物区系组成。本文对仔猪肠道微生物与脂质代谢-免疫应答网络之间的关系进行了综述,并总结了饲粮添加脂肪酸对断奶仔猪肠道免疫反应、微生物区系组成和脂质代谢的影响和作用机制,旨在为应用脂肪酸改善仔猪肠道健康提供参考。     

丁酸盐在仔猪肠道健康调节中的应用研究进展

断奶会造成仔猪肠道应激反应，损伤肠道机械屏障，削弱肠道消化吸收和抗病能力，引起其采食量低下、生长迟滞、消化功能紊乱等，甚至导致死亡。目前，开发绿色有效的饲料添加剂来替代抗生素用于改善断奶仔猪肠道健康，提高生产效率，是养殖行业关注的焦点。丁酸盐已被证明有益于动物肠道健康，且被用于改善仔猪肠道健康，但相关研究结果和应用效果不一致。本文主要综述了丁酸盐通过肠上皮细胞增殖、肠道机械屏障功能、肠道黏膜免疫力以及肠道微生物群对仔猪肠道健康的影响，从而为仔猪日粮中丁酸盐的应用提供参考。     

肠道微生物区系对断奶仔猪肠道黏膜免疫功能的调节作用研究进展

断奶仔猪肠道中定植了大量微生物,这些微生物及其代谢产物可参与断奶仔猪的肠道黏膜免疫过程。肠道微生物对断奶仔猪肠道黏膜免疫的调节机制主要是通过TLRs和NLRs通路分子分别发生作用。本文对肠道黏膜免疫的特点及断奶仔猪肠道微生物区系的组成进行了综述,并深入探讨了肠道微生物对断奶仔猪肠道黏膜免疫功能的调节作用,以及肠道微生物对肠道黏膜免疫系统调控的潜在机制,旨在为进一步利用断奶仔猪肠道黏膜免疫维持机体健康的相关研究提供参考。     

酵母菌能够平衡哺乳仔猪断奶时胃肠道菌群组成

猪肠道菌群由800余种细菌组成,这些细菌是其抵御病原微生物入侵的第一道屏障。肠道微生物则是以维持仔猪断奶时肠道微生物平衡和稳定为目的的日粮干预策略的一个重要指标。     

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。     

猪肠道微生物及其代谢产物与肠道屏障研究进展

肠道微生物参与营养物质代谢，影响猪的健康和发育，当肠道微生物发生紊乱，会造成猪腹泻并引起炎症反应，因此肠道微生物对猪的健康起着至关重要的作用。本文从肠道微生物在仔猪不同发育阶段的分布、肠道微生物的代谢产物对肠道健康的影响机制和肠道微生物与肠道屏障之间的关系进行阐述，并探讨了目前肠道健康研究的进展以及今后的研究方向，旨在为猪肠道健康调控提供理论参考。     

几种常用饲料添加剂对断奶仔猪肠道菌群调控的研究进展

早期断奶是现代养猪生产中的瓶颈问题。早期断奶易造成仔猪早期断奶综合征,仔猪断奶后会出现采食量下降、生长阻滞和腹泻等一系列症状。引起这些症状的主要原因之一是断奶应激引起的仔猪肠道屏障受损。鉴于肠道微生态区系为肠道第一道防御屏障,因此,研究仔猪肠道微生态区系及其营养调控技术,对于防制仔猪早期断奶综合征、促进仔猪肠道健康、提高生产性能具有重要意义。文章针对断奶仔猪肠道微生物菌群变化及几种常用饲料添加剂（微生态制剂、植物多糖、酸化剂、微量元素、中草药及植物提取物）对肠道微生态区系调控的研究进展进行了综述。     

日粮纤维调节猪肠道微生物和肠黏膜屏障功能的研究进展

仔猪腹泻难题制约生猪养殖水平的提高。随着高铜、高锌、抗生素的限用禁用,仔猪腹泻亟需"绿色"替代方案。日粮纤维作为第六大营养素,具有维持肠道健康的生理功能。日粮纤维可以通过优化肠道菌群结构,调节黏膜屏障等作用促进猪肠道的健康发育与完整功能实现。文章就日粮纤维对猪肠道微生物以及黏膜屏障功能的可能作用途径以及相关作用机制进行综述,以促进日粮纤维在猪日粮生产上应用,尤其是仔猪日粮生产上的合理广泛利用。     

肠道微生物-上皮细胞屏障互作的研究进展

肠道上皮细胞（intestinal epithelial cells,IECs）是动物机体抵御病原微生物的第一道防线,是黏膜机械屏障、免疫屏障和化学屏障的重要组成部分,具有吸收和屏障双层功能。肠道中微生物数量庞大、种类繁多,根据其与宿主的关系,主要分为共生菌、条件致病菌和病原菌3类,在肠道屏障的构建中发挥重要作用。IECs首先通过直接或间接方式对肠道微生物进行识别,区别自身与非自身,对自身物质（即共生菌）免疫耐受,对非自身物质（即病原菌）产生特异性免疫反应。IECs与肠道共生菌共同抵御肠道病原微生物,维持肠道健康,病原微生物侵入肠道,IECs主要通过胞外分泌物和细胞表面黏液层双重屏障发挥作用,其中胞外分泌物主要包括黏蛋白、抗菌分子和抗微生物免疫球蛋白。肠道共生菌可以通过竞争识别位点,分泌抗菌物质,增加黏液分泌,诱导IECs更新、增殖和修复等方式抵御病原微生物,维护正常的肠黏膜屏障功能。在IECs抵御肠道病原微生物入侵过程中,病原微生物通过自身运动、分泌毒素和酶等破坏肠上皮屏障,直接接触IECs,对其进行损伤。因此IECs和肠道菌群间相互作用,共同维持肠道内环境稳态。作者就IECs和肠道微生物结构、功能的适应性变化作一综述,以期阐述肠道微生物-上皮细胞屏障互作的机制。     

脱氧雪腐镰刀菌烯醇对仔猪肠道健康影响的研究进展

猪对脱氧雪腐镰刀菌烯醇(DON)的敏感性明显高于其他动物,其肠道是接触和吸收DON的主要场所。仔猪由于肠道发育尚未完善,容易受到DON污染引起肠道上皮细胞凋亡,促使肠道自由基和促炎性细胞因子分泌增加,破坏紧密连接蛋白,导致肠道形态结构和屏障功能损伤,打破肠道微生物区系平衡,从而影响仔猪肠道健康和正常生长。本文将围绕肠道形态结构、肠道屏障、肠道微生物、肠道黏膜免疫和肠道氧化应激等方面对近年来有关DON影响仔猪肠道健康的研究进行综述,以期为饲料中DON污染的防治措施以及仔猪肠道健康的营养调控提供科学依据。     

外源粪菌干预对受体猪肠道屏障功能的影响研究

为研究外源粪菌干预对受体猪肠道屏障功能的影响,试验选取初生重相近、胎次相同、同日出生的杜×长×大三元杂交哺乳仔猪12窝,随机分为2组,每组6窝(每窝10~12头)。试验组于1~10日龄隔天灌喂1 m L金华猪粪菌悬液进行外源粪菌干预;对照组灌喂等量无菌0.1 mol/L无菌磷酸盐缓冲液(PBS)。试验期间,仔猪自由哺乳采食和饮水,分别于12日龄和27日龄进行屠宰、采样。结果表明:外源粪菌干预可明显减少腹泻,提高受体猪的平均日增重和成活率(P0.05);外源粪菌干预能显著降低27日龄受体猪肠道隐窝深度(P0.05),显著提高肠道绒毛高度/隐窝深度(P0.05);外源粪菌干预能显著增加肠道杯状细胞数和12日龄肠道分泌型免疫球蛋白A阳性(SIgA~+)细胞数(P0.05),同时显著提高肠道黏蛋白Muc2、紧密连接蛋白ZO-1和Occludin表达水平(P0.05),而27日龄试验组的肠道SIgA~+细胞数与对照组无显著差异(P0.05)。综上可知,外源粪菌干预能通过增加肠道杯状细胞和SIgA~+细胞数、提高黏蛋白和紧密连接蛋白表达的方式调节受体猪肠道屏障功能,具有维持猪肠道功能稳态和促进肠道健康的作用。     

Gut microbiota absence and transplantation affect growth and intestinal functions: An investigation in a germ-free pig model

This study was conducted to investigate host–microbiota interactions and explore the effects of maternal gut microbiota transplantation on the growth and intestinal functions of newborns in a germ-free (GF) pig model. Twelve hysterectomy-derived GF Bama piglets were reared in 6 sterile isolators. Among them, 6 were considered as the GF group, and the other 6 were orally inoculated with healthy sow fecal suspension as fecal microbiota transplanted (FMT) group. Another 6 piglets from natural birth were regarded as the conventional (CV) group. The GF and FMT groups were hand-fed with Co60-γ-irradiated sterile milk powder, while the CV group was reared by lactating Bama sows. All groups were fed for 21 days. Then, all piglets and then were switched to sterile feed for another 21 days. Results showed that the growth performance, nutrient digestibility, and concentrations of short-chain fatty acids in the GF group decreased (P < 0.05). Meanwhile, the serum urea nitrogen concentration and digesta pH values in the GF group increased compared with those in the FMT and CV groups (P < 0.05). Compared with the CV group, the GF group demonstrated upregulation in the mRNA expression levels of intestinal barrier function-related genes in the small intestine (P < 0.05). In addition, the mRNA abundances of intestinal development and absorption-related genes in the small intestine and colon were higher in the GF group than in the CV and FMT groups (P < 0.05). The FMT group exhibited greater growth performance, lipase activity, and nutrient digestibility (P < 0.05), higher mRNA expression levels of intestinal development and barrier-related genes in the small intestine (P < 0.05), and lower mRNA abundances of pro-inflammatory factor in the colon and jejunum (P < 0.05) than the CV group. In conclusion, the absence of gut microbes impaired the growth and nutrient digestibility, and healthy sow gut microbiota transplantation increased the growth and nutrient digestibility and improved the intestinal development and barrier function of newborn piglets, indicating the importance of intestinal microbes for intestinal development and functions.     

粪菌移植改善猪肠道屏障功能的研究进展

肠道菌群是动物肠道系统组成的重要部分，对动物肠道发育和免疫功能成熟起着重要的作用，而且肠道菌群失衡与多种肠道疾病有关。粪菌移植（FMT）是一种将健康供体粪便菌群移植到患病受体肠道内，通过改善肠道菌群治疗肠道疾病的方法，是改善肠道菌群最直接、快速、有效的方法之一。近期的研究表明，FMT对畜禽肠道健康和生长性能有积极作用，可调节肠道菌群、维护肠道机械屏障、改善肠道黏液环境、提高肠道免疫力，对于维护肠道健康有很好的效果。本文综述了FMT对猪肠道屏障的影响，探讨了FMT的安全性和注意事项，以期为FMT技术在猪生产上更加安全规范的应用提供参考。     

Host genotype and amoxicillin administration affect the incidence of diarrhoea and faecal microbiota of weaned piglets during a natural multiresistant ETEC infection

Enterotoxigenic Escherichia coli (ETEC) is the aetiological agent of postweaning diarrhoea (PWD) in piglets. The SNPs located on the Mucine 4 (MUC4) and Fucosyltransferase 1 (FUT1) genes have been associated with the susceptibility to ETEC F4 and ETEC F18, respectively. The interplay between the MUC4 and FUT1 genotypes to ETEC infection and the use of amoxicillin in modifying the intestinal microbiota during a natural infection by multiresistant ETEC strains have never been investigated. The aim of this study was to evaluate the effects of the MUC4 and FUT1 genotypes and the administration of amoxicillin through different routes on the presence of diarrhoea and the faecal microbiota composition in piglets naturally infected with ETEC. Seventy-one piglets were divided into three groups: two groups differing by amoxicillin administration routes—parenteral (P) or oral (O) and a control group without antibiotics (C). Faecal scores, body weight, presence of ETEC F4 and F18 were investigated 4 days after the arrival in the facility (T0), at the end of the amoxicillin administration (T1) and after the withdrawal period (T2). The faecal bacteria composition was assessed by sequencing the 16S rRNA gene. We described that MUC4 and FUT1 genotypes were associated with the presence of ETEC F4 and ETEC F18. The faecal microbiota was influenced by the MUC4 genotypes at T0. We found the oral administration to be associated with the presence of diarrhoea at T1 and T2. Furthermore, the exposure to amoxicillin resulted in significant alterations of the faecal microbiota. Overall, MUC4 and FUT1 were confirmed as genetic markers for the susceptibility to ETEC infections in pigs. Moreover, our data highlight that group amoxicillin treatment may produce adverse outcomes on pig health in course of multiresistant ETEC infection. Therefore, alternative control measures able to maintain a healthy faecal microbiota in weaners are recommended.     

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。     

Dietary copper/zinc-loaded montmorillonite improved growth performance and intestinal barrier and changed gut microbiota in weaned piglets

The effects of copper/zinc-loaded montmorillonite (Cu/Zn-Mt) on growth performance, intestinal barrier and gut microbiota of weaned pigs were investigated in the present study. A total of 108 piglets (Duroc × Landrace × Yorkshire; 6.36 kg; weaned at 21 ± 1 d age) were used in this experiment. The pigs were randomly assigned to three treatments with six replicates, six pigs in each replicate. The three treatments were as follows: (1) control group: basal diet; (2) Cu/Zn-Mt group: basal diet supplemented with 39 mg/kg Cu and 75 mg/kg Zn as Cu/Zn-Mt; and (3) Cu +Zn +Mt group: basal diet supplemented with the mixture of copper sulphate, zinc sulphate and montmorillonite (equivalent to the copper and zinc in the Cu/Zn-Mt treatment). The results indicated that, compared with the pigs from control group, average daily gain and gain: feed ratio were increased and the faecal score on days 7 and 14 after weaning was decreased by supplementation of Cu/Zn-Mt; intestinal transepithelial electrical resistance (TER) and expressions of tight junction protein claudin-1 and zonula occludens-1 were increased, and intestinal permeability of fluorescein isothiocyanate-dextran 4 kDa was decreased by supplementation with Cu/Zn-Mt. According to the Illumina-based sequencing results, Cu/Zn-Mt supplementation increased the relative abundance of core bacteria (Lactococcus, Bacillus) at genus level and decreased the potentially pathogenic bacteria (Streptococcus and Pseudomonas) in colon of weaned piglets. However, the piglets fed with the mixture of copper sulphate, zinc sulphate and montmorillonite showed no effects in above parameters in comparison with the pigs from control group. In conclusion, dietary Cu/Zn-Mt could improve growth performance, decrease the diarrhoea and improve intestinal barrier and bacterial communities of weaned pigs. The results indicated that ‘loading’ of montmorillonite with Zn and Cu changed not only its chemical but also its nutritional properties.     

Research Advances on Intestinal Microflora Regulationin by Several Feed Additives in Piglets

In modern pig production,early weaning is a bottleneck problem which are restricting the development of pig industry.It can lead to early weaning syndrome in piglet,such as low appetite,growth inhibition,diarrhea and so on.One of the reasons induced these symptoms is impairment of intestinal mucosal barrier in piglets.The intestinal microflorais is one of the important parts of intestinal mucosal barrier.Therefore,study on the intestinal microflora of weaning piglets and nutritional regulations have been attracted more and more attentions,and it has an important influence on avoiding diarrhea,promoting the healthy growth and improving growth performance.The change of intestinal microflora in weaning piglets and research development of some common feed additives（microecologics,plant polysaccharide,acidulant,microelement,Chinese herbal medicine and plant extracts）for intestinal microflora were reviewed in this paper.     

不同粪菌悬液处理方式对猪粪菌移植过程中细菌活性及活菌组成的影响

旨在探究不同粪菌液处理方法对其菌群活性及存活菌群物种组成的影响,为猪粪菌移植（FMT）的优化应用提供参考。本研究共设置7个试验组制备粪菌液：静置制备新鲜粪菌液组（FS）、静置制备粪菌液于-80℃冷冻1周组（FFS）、离心制备新鲜粪菌液组（FC）、离心制备粪菌液于-80℃冷冻1周组（FFC）、液氮冷冻粪便24 h静置制备粪菌液组（NS）、甘油+液氮冷冻粪便24 h静置制备粪菌液组（GNS）和液氮冷冻粪便24 h静置制备粪菌液于-80℃冷冻1周组（NFS）,在37℃厌氧培养箱中平板培养48 h后,进行菌落计数。从FS、FFS、FC和FFC 4组中根据菌落形态随机挑取87个单菌落纯化后进行16S rRNA基因全长测序。结果表明,静置和离心两种方法制备新鲜粪菌液时,粪菌活性存在显著差异,离心组显著低于静置组（P<0.05）。但冷冻粪便使用静置和离心两种方法制备的菌悬液,其粪菌活性无显著差异（P>0.05）。无论是静置还是离心方法制备粪菌液,新鲜和冷冻两种不同处理方式下的粪菌活性均无显著差异（P>0.05）,且对活菌的组成也无显著影响。使用静置法制备粪菌液时,FS、NS、GNS和NFS组间粪菌活性无显著差异（P>0.05）。综上表明,静置方法制备粪菌液时,超低温冷冻保存对粪菌活性及其活菌组成均无显著影响,这为大样本、长距离猪粪菌移植技术的应用提供了重要试验参考。