低聚果糖调节人体肠道菌群功能的研究

为了研究低聚果糖调节人体肠道菌群的功能和效果,采用卫生部《保健食品检验与评价技术规范》调节肠道菌群功能检验方法进行检验,并将体检指标全部合格的120例成年志愿者随机分为试食组和空白对照组,试食组每天分别服用含量大于等于55%的低聚果糖6mL,空白组则采用果葡糖浆作为安慰剂,连续30d,比较摄食前后两组肠道菌群的变化情况。试验结果表明,试食组试验后较试验前粪便中双歧杆菌数量增加5.8%(P0.01),乳酸杆菌增加0.4%(P0.05),产气荚膜梭菌数量减少8.6%(P0.01),拟杆菌数量增加1.0%(P0.01),肠杆菌和肠球菌分别增加0.4%和0.8%(P0.05);与对照组相比,试验后试食组双歧杆菌增加4.2%(P0.01),乳酸杆菌减少21%(P0.05),产气荚膜梭菌减少7.2%(P0.01),拟杆菌减少0.4%(P0.05),而肠杆菌和肠球菌数量无明显变化(P0.05)。因此,每日摄食3.3g的低聚果糖亦具有调节人体肠道菌群,激活益生菌增殖并抑制有害菌的作用。     

低聚木糖的特性及其在乳制品中的应用

低聚木糖又称木寡糖,是指2～7个木糖分子以β-1,4糖苷键连接而成的功能性聚合糖。它在国外被誉为超强双歧杆菌增殖因子,其增殖功能约是其它低聚糖的20倍,且对双歧杆菌有高效选择性增殖效果。与其它低聚糖相比,即使微量地摄入,也可增加体内双歧杆菌的数量。当前,用低聚糖作为优良的双歧因子来源,不仅     

绿色饲料添加剂——低聚木糖的特性、功能及应用

低聚木糖是以富含木聚糖的植物为原料,通过生物化学方法生产的一类功效突出的功能性低聚糖,具有显著地增殖肠道益生菌的功能,现已成为一种新型绿色饲料添加剂。对低聚木糖的概念、特性、功能、生产及在动物饲养中的应用进行了阐述,分析了目前低聚木糖在开发和研究中所存在的问题,并对其应用前景进行了展望。     

低聚木糖梯度添加对异育银鲫生长及肠道消化酶活性的影响

选1年异育银鲫80尾,随机分为4组,每组2个重复。第1组为对照组,饲喂基础日粮;第2、3、4组分别在基础日粮中添加0.005%、0.01%和0.02%的低聚木糖,研究不同添加梯度对异育银鲫生长和肠道消化酶活性的影响,并确定最合适的添加比例。结果表明,添加低聚木糖能够提高异育银鲫的生长和肠道消化酶活性,其中以0.01%的添加比例增重效果较好;若添加过量,生长和蛋白酶活性出现下降趋势,而淀粉酶活性则没有明显的变化。     

低聚木糖对肉鸭生长性能的影响

低聚木糖（Xylo-oligosacchariddes，XOS）是从富含木聚糖的天然植物中经生物技术提取出的2。7个木糖以β-1，4糖苷键连接而成的低度聚合糖类的总称，以二糖和三糖为主。作为一种新型的寡聚糖添加剂，低聚木糖是低聚糖种类中增殖双歧杆菌功能最好、抑制病原菌和腐败菌生长、净化肠道功效最佳的产品之一。     

低聚木糖、益生菌及抗生素对肉鸡肠道菌群和生产性能的影响

选用1日龄健康AA肉雏鸡1200羽,随机分成6个处理,每个处理8个重复,分别饲喂添加抗生素(杆菌肽锌16.7mg·kg-1和硫酸粘杆菌3.3mg·kg-1,对照组)、低聚木糖(0.02%)、合生素(0.005%益生菌+0.005%及0.01%低聚木糖)、抗生素与低聚木糖(对照组抗生素+0.005%及0.01%低聚木糖)6种不同日粮,研究不同处理对肉鸡肠道微生物菌群和生产性能的影响。结果表明:与对照组相比,各试验组肉鸡空肠的乳酸菌数分别提高了19.89%(P<0.05)、9.17%、20.21%(P<0.05)、13.98%(P<0.05)和16.75%(P<0.05),除0.005%低聚木糖+抗生素组,其它各组大肠杆菌数量均较高。各试验组前期(0～21日)、后期(22～42日)和全期(0～42日)的肉鸡体增重分别提高了0.8%～15.1%、2.9%～29.0%和2.2%～24.0%,后期和全期饲料转化率分别改善了2.5%、4.3%、10.4%、16.9%、12.5%和1.0%、3.3%、6.2%、7.1%、6.2%,以添加0.005%低聚木糖+抗生素组的肉鸡增重、饲料转化率与成活率为最佳。     

绿色饲料添加剂——低聚木糖

低聚糖，亦称寡糖，是由2～8个单糖分子通过糖苷键构成的聚合物，并根据糖苷键不同有不同的名称，如低聚木糖、低聚果糖和低聚甘露糖等。低聚糖作为双歧杆菌生长促进因子，是20世纪70年代日本东京大学光罔教授发现的。因其具有独特的生理功能，而广泛用于食品和饲料生产中，并为各国政府批准，承认其可促进双歧杆菌生长，有良好的整肠功效。     

低聚木糖对草鱼非特异性免疫功能的影响

本试验旨在研究低聚木糖对草鱼非特异性免疫功能的影响.将525尾规格、体重基本一致的健康草鱼随机分为5组(每组设3个重复,每个重复35尾),分别饲喂在基础饲料中添加0(A0组)、1(A1组)、2(A2组)、4(A3组)和6 g/kg(A4组)低聚木糖的饲料.分别于试验第0天、第7天、第14天、第28天、第56天检测草鱼血液中白细胞吞噬活性,血清溶菌酶、超氧化物歧化酶活性和补体C3含量.在养殖试验(56 d)结束后连续攻毒14 d,计算各组试验鱼攻毒后死亡率.结果表明,与对照组相比,在整个试验期内,各试验组草鱼的各项免疫指标均有不同程度的提高.其中,A3组的白细胞吞噬活性,血清溶菌酶、超氧化物歧化酶活性和补体C3含量均显著高于A0组(P<0.05),并分别于第28天、第28天、第7天、第28天达到最大值,而且其攻毒后死亡率最低.结果提示,饲料中添加低聚木糖可提高草鱼非特异性免疫功能,其最佳添加量为4 g/kg.     

低聚木糖在猪生产中的应用

本文就低聚木糖的生物学特性及其在猪生产中的应用作一综述。     

低聚木糖对肉仔鸡生长性能的影响

低聚木糖（Xylo—oligosaccharides，XOS）是从富含木聚糖的天然植物中经生物技术提取的由2～7个木糖以8—1，4糖苷键连接而成的低度聚合糖类的总称，以二糖和三糖为主。作为一种新型的寡聚糖添加剂，与其他功能性寡聚糖相比，XOS具有稳定性好、对双歧杆菌选择性高以及能促进钙质吸收等独特的优点，因此作为优良的双歧杆菌增殖因子而倍受关注。有关寡聚糖的作用机制及应用效果已作了很深入的研究，但大多是从机体免疫及消化道微生态的角度着手，对家禽消化生理方面的研究报道较少，因而有必要开展此方面的研究。试验以XOS为材料，研究其对肉仔鸡生产性能的影响，并探讨适宜添加量，为其在肉仔鸡饲粮中的应用提供理论依据。     

Opportunities of prebiotics for the intestinal health of monogastric animals

The goal of prebiotic applications from different sources is to improve the gut ecosystem where the host and microbiota can benefit from prebiotics. It has already been recognized that prebiotics have potential roles in the gut ecosystem because gut microbiota ferment complex dietary macronutrients and carry out a broad range of functions in the host body, such as the production of nutrients and vitamins, protection against pathogens, and maintenance of immune system balance. The gut ecosystem is very crucial and can be affected by numerous factors consisting of dietary constituents and commensal bacteria. This review focuses on recent scientific evidence, confirming a beneficial effect of prebiotics on animal health, particularly in terms of protection against pathogenic bacteria and increasing the number of beneficial bacteria that may improve epithelial cell barrier functions. It has also been reviewed that modification of the gut ecosystem through the utilization of prebiotics significantly affects the intestinal health of animals. However, the identification and characterization of novel potential prebiotics remain a topical issue and elucidation of the metagenomics relationship between gut microbiota alteration and prebiotic substances is necessary for future prebiotic studies.     

肠道黏膜屏障机能及其调控研究进展

肠道不仅仅是机体消化、吸收营养物质的主要场所,也是机体的一道防御屏障。肠道黏膜屏障包括黏膜生物屏障、机械屏障、化学屏障和免疫屏障,不论是哪一种肠道黏膜屏障受到损伤,都会导致机体不同程度的伤害,与一些疾病的发生密切相关。本文就肠道黏膜屏障机能及其调控研究进展进行综述,为进一步认识肠道黏膜屏障及治疗由其损伤引起的疾病提供参考和帮助。     

动物肠道免疫的构成与功能

肠道作为机体重要的组成部分,人们对它的认识长期集中在对营养物质的消化和吸收上。近年来随着对机体组织器官的深入研究和科研手段的进步,胃肠的研究工作也从单纯的养分消化向全方位发展。正常情况下,肠道可有效阻挡肠内500多种、浓度高达10^12个/g的肠道内寄生菌及其毒素向肠外组织移位,同时产生高效的细胞和体液免疫,防止内源性微生物及其毒素的侵害;对于无害抗原（食物或正常菌群）,肠黏膜可下调免疫应答反应,保证机体及时获得养分,     

Effect of xylo-oligosaccharides from corn cobs autohydrolysis on the intestinal microbiota of piglets after weaning

The effect of xylo-oligosaccharides (XOS), a probiotic culture of Saccharomyces cerevisiae (SC) and the combined administration of XOS and SC on the piglet intestinal microbiota was investigated. Twenty four weaned piglets were fed during 4 weeks with one of the following diets: (BD) basal diet; (BD + XOS) basal diet supplemented with xylo-oligosaccharides (20 g kg^− 1); (BD + SC) basal diet supplemented with S. cerevisiae (6 × 10⁹ CFU kg^− 1); and (BD + XOS + SC) basal diet supplemented with xylo-oligosaccharides and S. cerevisiae. Samples from the ileum, caecum and colon were collected and analysed for total anaerobes growing in XOS or glucose, xylose and arabinose (GXA) containing media. Specific primers were used to evaluate differences in Bifidobacterium and Lactobacillus populations and ERIC PCR to fingerprint the intestinal microbiota.

The lowest number of culturable bacteria was obtained from the ileum of animals fed BD + XOS. The highest PCR titres with Lactobacillus group-specific primers in BD and BD + SC were obtained in the caecal contents. In XOS-supplemented diets the PCR titres were increased or maintained, from the caecum to the colon. Bifidobacteria were not detected in any samples using genus-specific primers. In the dendrogram from ERIC PCR, the piglets fed with XOS diets presented the highest similarity between samples and probiotic reference strains.     

褪黑激素对免疫功能的影响

Lerner等（1958）第一次从牛的松果腺中分离出褪黑激素后,它就被认为是一种与松果腺联系在一起的内分泌激素。然而,在过去的几年中,由于特异性强的抗体和检测方法的出现,使我们在除了松果腺以外的许多机体组织中发现有褪黑激素的存在,其中包括免疫系统。19世纪60年代,松果腺代谢的主要途径被揭示。褪黑激素对人的生长发育、生殖和代谢起着重要作用,其昼低夜高的分泌规律决定了人类昼夜节律生物钟的正常运行。近年的研究表明,褪黑激素对机体有着广泛的影响,     

Low crude protein diets supplemented with casein hydrolysate enhance the intestinal barrier function and decrease the pro-inflammatory cytokine expression in the small intestine of pigs

To reduce nitrogen excretion and lower feeding costs, low crude protein (CP) diets are sometimes proposed, however, a great reduction of dietary CP concentration (>4% reduction vs. recommended concentration), even supplemented with essential and nonessential amino acids (AA) can detrimentally affect small intestinal barrier function and immunity, possibly due to the excessive lack of peptides. Here we hypothesize that with an extremely low CP concentration diet, protein-derived peptides, rather than AA supplementation, can improve intestinal barrier development and health. To test this hypothesis, 21 growing pigs (19.90 ± 1.00 kg body weight) were randomly assigned to 3 treatments with control diet (16% CP), or low CP diets (13% CP) supplemented with AA (LCPA) or casein hydrolysate (LCPC) for 28 days. In comparison with the control diet, the LCPA diet decreased the protein expression level of jejunal barrier factor zonula occludens-1 (ZO-1) and stem cell proliferation factor leucine-rich repeat-containing G-protein-coupled receptor-5, whereas the LCPC diet enhanced intestinal barrier function by increasing the protein expression level of jejunal occludin and ZO-1 and ileal mucin-2. The LCPA diet reduced Lactobacillus counts, whereas the LCPC diet increased Lactobacillus counts and reduced Escherichia coli counts in the ileum. The LCPA diet also increased protein expression levels of pro-inflammatory cytokine interleukin-6 (IL-6) and IL-22, whereas the LCPC diet decreased protein expression levels of pro-inflammatory IL-1β, IL-17A and tumor necrosis factor-α in the ileum. Collectively, the casein hydrolysate supplementation of low CP diets showed beneficial effects on the small intestinal barrier, bacterial community, and immunity in pigs, pointing to the important role of protein-derived peptides in small intestinal health in cases of low crude protein diets.     

乳酸菌对仔猪生长性能、免疫功能和肠道菌群的影响

文章旨在探究饲料中添加乳酸菌对仔猪生长性能、免疫功能和肠道菌群的影响,试验以360头仔猪为研究对象,根据乳酸菌的添加量划分为6组,对照组饲喂常规饲料,其余5组中饲料乳酸菌的添加水平分别为0.25%,0.5%,0.75%,1%和1.25%,分别投喂对应的饲料,饲养试验为期35 d。结果表明：随着饲料中乳酸菌添加水平的不断上升,0.75%组仔猪日均采食量显著高于对照组（P＜0.05）,对仔猪料重比无显著影响（P＞0.05）|在各个饲料添加组中,0.75%组中仔猪的腹泻率明显低于对照组（P＜0.05）|在所有试验组中,0.75%组仔猪的免疫球蛋白A,M和补体C3的含量显著高于对照组（P＜0.05）|随着饲料中乳酸菌含量的不断增加,仔猪血清IL-6和IL-8含量先下降后上升,TNF-α的含量不断下降|对仔猪大肠杆菌和双歧杆菌的含量无显著影响（P＞0.05）。因此,饲料中添加适宜水平的乳糖菌能显著提高仔猪日增重、平均日采食量和动物的生长发育速度,降低仔猪腹泻率、机体炎症反应,增强动物免疫功能。[关键词]乳酸菌|仔猪|免疫功能|肠道菌群     

N-Acetyl-D-glucosamine improves the intestinal development and nutrient absorption of weaned piglets via regulating the activity of intestinal stem cells

Early weaning in piglets can cause a series of negative effects.This causes serious losses to the livestock industry.N-Acetyl-D-glucosamine(D-GlcNAc)plays an important role in regulating the homeostasis of the intestine.This study aimed to investigate the effects of D-GlcNAc on the growth performance and intestinal function of weaned piglets.Twenty-four weaned piglets([Yorkshire×Landrace]
Duroc,6.58±0.15 kg,n=8)at 21 d old were fed 3 diets supplemented with 0(control),1 and 3 g/kg D-GlcNAc.The intestinal organoid model was used to verify the regulatory mechanism of D-GlcNAc on intestinal epithelial cells.On the whole,supplementation of D-GlcNAc in the piglet diet has no significant effect on the growth performance and diarrhoea of weaned piglets(P>0.05).The apparent digestibility of nutrients and mRNA abundance of nutrient transporters in the 1 g/kg D-GlcNAc group were increased significantly(P<0.05).D-GlcNAc did not affect villus height(VH)and crypt depth(CD)but resulted in a numerically shorter VH and shallower CD,which lead to an increase in ileal VH:CD ratio(P<0.05).Cell shedding rates in the ileum villi increased(P<0.05).The relative length and weight of the small intestine of weaned piglets increased(P<0.05).In vitro studies found that the budding rates of organoids treated with 0.1 mmol/L D-GlcNAc increased on the d 3 and 5(P<0.05).The average budding numbers per budding organoid treated with 0.1 and 10 mmol/L D-GlcNAc increased on d 3(P<0.05).D-GlcNAc upregulated leucine rich repeat containing G protein-coupled receptor 5(Lgr5⁺)and Chromogranin A mRNA abundance in organoids(P<0.05).Mucin 2(Muc2)expression increased when treated with 1 and 10 mmol/L D-GlcNAc(P<0.05).In conclusion,dietary D-GlcNAc cannot improve the growth performance of weaned piglets.However,it can promote the growth and development of the intestinal tract and improve the digestion and absorption capacity of the intestine,which is achieved by affecting the activity of intestinal stem cells.     

小麦型日粮中添加木聚糖酶对肉鸭生产性能的影响

本试验在小麦型基础日粮中分别添加木聚糖酶0、50、100、150、200g/t饲料(5000U/g酶)饲喂12日龄樱桃谷肉鸭,观察木聚糖酶对肉鸭生产性能的影响。结果表明:添加木聚糖酶对肉鸭生产性能影响不显著(P0.05),单位增重饲料成本以添加量50 g/t(即每1 kg饲料含250 U木聚糖酶)的有效含量为佳。