1株动物双歧杆菌的分离鉴定及其对小鼠溃疡性结肠炎的调理作用

为了探讨双歧杆菌对小鼠溃疡性结肠炎的作用,本试验从新鲜的婴儿粪便中分离筛选出具有典型双歧杆菌形态的菌株,用16S RNA通用引物和细菌生化试验进行菌种鉴定,并对该菌株进行了生产性能测定。通过建立硫酸葡聚糖钠盐(dextransulfatesodium, DSS)诱导的小鼠溃疡性结肠炎模型,评估该菌株对小鼠溃疡性结肠炎的作用。结果显示,新鲜婴儿粪便中分离的菌株经16S RNA保守序列和细菌生化试验鉴定为动物双歧杆菌(被命名为NFTY9),该菌株能够显著降低由DSS引起的小鼠腹泻和便血现象,改善肠道肠黏膜损伤,降低肠道炎性因子TNF-α和IL-6含量。结果表明,动物双歧杆菌NFTY9具有显著改善小鼠溃疡性结肠炎的作用,为进一步开发应用提供了理论依据。     

双歧杆菌的研究与应用

双歧杆菌(Bifidobacteria)是人和许多哺乳动物肠道中的优势菌之一,在微生态学上属于原籍菌群.1899年法国巴斯德研究院的Tidder首次从母乳喂养的婴儿大便中分离到了该菌,并指出它对乳儿的营养和预防肠道疾病具有重要作用.自那以后,经过人们多年不懈的研究,现已认识到该菌是人和动物肠道中重要的生理性细菌,参与免疫、营养、消化和保护等一系列的生理过程,发挥着重要的功能.本文就对双歧杆菌的形态特征、生理功能和双歧杆菌制剂的应用综述如下.     

基于体外模拟肠道微生态系统的乳双歧杆菌MN-Gup益生元筛选及其发酵特性研究

体外肠道微生态模拟是一种研究食源性成分对肠道菌群组成和代谢产物组成的手段。本研究建立了成人的体外肠道菌群生态模拟体系,研究筛选低聚果糖、低聚半乳糖、菊粉、低聚木糖和低聚甘露糖与乳双歧杆菌MN-Gup协同增效调节肠道有益菌的作用。结果表明,添加1.5%比例低聚木糖组能够显著提升菌群中双歧杆菌的比例,而同样添加1.5%的低聚半乳糖组对乳杆菌提升更为明显,各益生元组对阿克曼菌的比例并无显著影响,菊粉组可以显著提升厚壁菌门/拟杆菌门的比值。以上结果表明,乳双歧杆菌的不同合生元组合对于肠道菌群的调控作用有明显差异,在体外肠道模拟体系下含有低聚木糖的合生元组合更有助于提高菌群中双歧杆菌的比例。     

双歧杆菌及其产品缓解肠炎症状的研究进展

双歧杆菌具有调节肠道菌群、缓解功能性胃肠道疾病的功能,是目前广为使用的用于改善人体肠道的益生菌之一。炎症性肠病（inflammatory bowel disease,IBD）是一种慢性复发性炎症性疾病,该疾病伴随着肠黏膜溃疡、细胞死亡,并且容易复发。近年来,相关报道在肠炎治疗方面提到了双歧杆菌的益生作用。本文概述双歧杆菌、双歧杆菌产品、双歧杆菌代谢物对IBD的缓解效果,为双歧杆菌在医药方面的应用提供新的研究方向。     

复合低聚糖对奶牛主要肠道菌体外生长的影响

双歧杆菌、乳酸杆菌和大肠杆菌是奶牛肠道正常微生物区系中的主要肠道菌,其中双歧杆菌和乳酸杆菌是重要的有益菌,大肠杆菌是最多的有害菌。这些细菌与宿主终生伴随,发挥着营养、免疫调节、生物屏障、维持肠道菌群平衡等重要作用。而异麦芽低聚糖、低聚果糖等低聚糖均为双歧杆菌、乳酸杆菌生长的增殖因子,属功能性低聚糖,可促进双歧杆菌、乳酸杆菌的生长。这些功能性低聚糖被有益菌利用后,代谢会产生醋酸及乳酸,使肠道呈酸性,抑制有害菌的增殖,促进肠道的蠕动,防止便秘和腹泻。本试验对复合低聚糖在体外对双歧杆菌、乳酸杆菌和大肠杆菌生长的作用进行了研究。     

低分子质量左聚糖对人体肠道菌群调节作用

采用三氯乙酸(trichloroacetic acid,TCA)法除去Paenibacillus bovis sp.nov BD3526来源的高分子质量左聚糖中蛋白质的同时制备得到低分子质量左聚糖,并用离子交换层析法对低分子质量左聚糖进行分离纯化,用凝胶渗透色谱(gel permeation chromatography,GPC)法测定纯化后样品的分子质量及其分布,用核磁共振(nuclear magnetic resonance,NMR)仪和傅里叶变换红外光谱(fourier transform infrared spectrometer,FT-IR)表征其化学结构,用原子力显微镜(atomic force microscope,AFM)表征其在水溶液中的构象,最后采用荷兰应用科学研究(The Netherlands Organization For Applied Scientific Research,TNO)组织建立的体外筛选平台评价其对人体肠道菌群的调节作用.体外实验结果表明,此低分子质量左聚糖能促进双歧杆菌特别是婴儿双歧杆菌和长双歧杆菌的增殖,其促进作用优于低聚果糖(fructooligosaccharide,FOS).     

双歧杆菌对功能性便秘影响的研究进展

功能性便秘是一种临床上比较常见的消化系统疾病,可引发一系列疾病,因此对该疾病的预防和治疗具有重要意义。双歧杆菌是肠道固有菌群之一,其对缓解功能性便秘有明显效果。本文从肠道菌群与功能性便秘的关系、双歧杆菌缓解便秘的机制以及双歧杆菌不同菌株缓解功能性便秘的效果等方面对双歧杆菌缓解功能性便秘的国内外研究进展进行综述,以期为双歧杆菌功能性菌株的深度开发及其用于缓解便秘机制的深入研究提供思路。     

胆盐水解酶筛选及酶法提制鸡胆汁酸的研究

试验旨在从常见双歧杆菌筛选获得高活性胆盐水解酶的菌株并用于鸡胆汁酸的提制。从5种常见双歧杆菌菌株(两歧双歧杆菌、婴儿双歧杆菌、青春双歧杆菌、乳双歧杆菌、长双歧杆菌)中，通过平板Ca²⁺沉淀法及茚三酮法对活性双歧杆菌进行酶活评价，将高活性菌株的粗酶用于鸡胆汁酸的提制，使用薄层色谱法和高效液相法对所制胆汁酸进行定性和定量检测。结果显示：4种双歧杆菌(两歧双歧杆菌、婴儿双歧杆菌、青春双歧杆菌和乳双歧杆菌)对甘氨型和牛磺型鹅去氧胆酸均具有水解活性，婴儿双歧杆菌对甘氨鹅去氧胆酸和牛磺鹅去氧胆酸比酶活均显著高于其他3种双歧杆菌(P<0.05)，比酶活分别为0.48 U/mg和0.27 U/mg。酶法工艺提制鸡胆汁酸的得率为5.34%，提取物中鹅去氧胆酸(CDCA)含量为70.7%。结果表明：婴儿双歧杆菌具有高活性胆盐水解酶，酶法工艺提制鸡胆汁酸反应条件温和，提取物纯度较高，较为节能环保。     

双歧杆菌及其后生素的益生功能与应用

双歧杆菌是动物和人体肠道菌群中早期优选定植的微生物，其菌体或失活的菌体细胞、菌体代谢物质或细胞裂解死亡后产生的脂质、蛋白质、维生素和碳水化合物等，具有促进营养物质消化吸收、增强机体免疫力和提高动物生产性能等功能。文章综述了双歧杆菌及其后生素与宿主健康之间的影响，为其在动物生产中发挥营养保健功能提供理论基础，促进畜牧业绿色健康发展。     

乳猪双歧杆菌的分离及其在饲料中的应用

双歧杆菌是人和动物肠道内的正常菌群之一,一般在动物出生后4—5天就成为最优势菌。双歧杆菌具有分解糖类,产生醋酸、乳酸等酸类,以稳定肠道内环境,抵御有害菌群的感染,促进消化等功能,因此对人和动物有益而无害。但是动物随着日龄的增加,环境条件的种种变化,尤其是动物饲料中抗菌素的添加,都会导致肠道内正常菌群紊乱,致使双歧杆菌在肠道菌群中的比例失调。其绝对含量日趋下降。人类根据该菌能在肠道定檀繁殖的特点,而制出含有双歧杆菌活菌的各种食品和饮料,人为地建立优势菌已经取得了很好的效果,增进了人体健康。在动物方面,曾有过活菌制剂治疗腹泻、白痢等病的报导,但是以双歧杆菌作为饲料添加剂的报导甚少。笔者应用从仔猪粪便中分离的双歧杆菌,经过纯化培     

用于肠道中的乳酸菌和双歧杆菌研究的分子生物学技术

综述了利用16S rRNA基因为靶基因的各种分子生物学技术来研究肠道中乳酸菌和双歧杆菌的方法，指出了肠道中乳酸菌和双歧杆菌的组成及其菌数。     

棉籽糖的生理功能及其在动物生产中的应用

棉籽糖是植物界中分布最广泛的低聚糖之一。棉籽糖能促进双歧杆菌的增殖和调节肠道菌群平衡,还具有免疫调节、抗氧化、保肝作用等特殊生理功能。文章综述棉籽糖的生理功能及其在动物生产中的应用研究进展,为棉籽糖在动物生产的应用中的进一步开发和利用提供参考。     

Bifidobacteria are obligate inhabitants of the crop of adult laying hens

Modified TPY agar (MTPY; with addition of glacial acetic acid and mupirocin) was used in the enumeration of bifidobacteria from hen crop and faeces. The colonies on MTPY medium inoculated with crop and faeces samples were Gram-stained, screened for presence of fructose-6-phosphate phosphoketolase activity and tested for fermentation patterns using ANAEROtest kits. It was revealed that bifidobacteria are obligate inhabitants of the hen crop, reaching counts of 10(7)/g of crop content. The occurrence of bifidobacteria in the hen crop was evidently not the consequence of ingestion of faeces as all the bifidobacteria strains isolated from the hen crop fermented glucose and fructose, while most strains isolated from hen faeces did not ferment either glucose or fructose. The results suggest that bifidobacteria are common and may even be one of the predominant parts of the hen crop flora.     

嗜酸乳杆菌、双歧杆菌和干酪乳杆菌的选择性计数

LC培养基只能计数干酪乳杆菌，MRS－水杨素（或山梨醇）培养基可以计数嗜酸乳杆菌和干酪乳杆菌，而MRS培养基可以计数嗜酸乳杆菌、干酪乳杆菌和双歧杆菌，于是通过减法原则就能从混合物中单独计数它们。另外，MRS－NNLP培养基也可用于选择性计数双歧杆菌。     

乳源低聚糖及其代谢的研究进展

乳源低聚糖因其独特的益生作用,受到人们的广泛关注.从组成上分析,不同哺乳动物来源的低聚糖成分和结构有差异.从代谢途径上分析,以双歧杆菌为代表的一些益生菌进化出了较为完整的乳源低聚糖代谢模式.从益生作用上分析,相较于其他来源的益生元,乳源低聚糖表现出更好的益生作用,如更好地增加肠道菌群的多样性、促进双歧杆菌的增殖等.     

Dietary effects on bifidobacteria and Clostridium perfringens in the canine intestinal tract

Dietary effects on the intestinal microflora have gained increasing interest because of the evidence that a balanced micro ecology in the gut is important for health and well being. The aim of the present study was to evaluate the effect of different diets on faecal counts of bifidobacteria and Clostridium perfringens in dogs. Two extruded, dry diets, one supplemented with 3% chicory (1.5% inulin), a non-digestible oligosaccharide (NDO) and the other with 3% glucose (GLU) were compared with a protein rich diet (PR+) based on low quality animal derived protein sources (NDO 265, GLU 259, PR+ 726 g crude protein/kg dry matter; greaves meal and bovine lung as protein sources in PR+). Nine adult beagles were subjected to a consecutive cross-over trial. All dogs started with diet PR+, after which groups of four dogs (group A) received GLU and the other five dogs (group B) received NDO. After an intermediate wash-out period with diet PR+ for 3 weeks the A dogs were switched to diet NDO and B dogs to GLU. In the final period all dogs were fed with diet PR+. Faecal samples were collected during each period for dry matter and pH measurements. Faecal bifidobacteria and Cl. perfringens were quantified in fresh samples at the end of each feeding period and additionally on the first days after feed change from the dry diets to diet PR+. Diets NDO and GLU increased faecal dry matter and reduced faecal pH from 6.9 to 7.4 with the high protein diet to 5.9-6.5. The dry diets induced a firmer faecal consistency and a lower faecal pH, with no significant difference between NDO or GLU. Clostridium perfringens was found in all faecal specimens after feeding PR+ with counts of log 8.2-8.8 colony forming units (cfu)/g faeces. Both dry diets reduced the counts of Cl. perfringens significantly (log 3.3-4.0 cfu/g faeces). Switching from the dry diets to the high protein diet induced an increase of Cl. perfringens within 1 day, independent of the previous diet. In dogs fed PR+, bifidobacteria were detected in only four faecal samples and exclusively in the initial feeding period. During the remainder of the experiment the counts fell below the detection limit (log 6 cfu/g faeces). The faecal concentrations of bifidobacteria increased with both dry diets. Slightly higher concentrations (log 9.6-9.7 cfu/g faeces) were obtained from dogs fed the dry diet containing NDO compared with the diet containing glucose (log 9.3-9.4 cfu/g faeces). The increase was small which may be related to the level of total fermentable carbohydrates in both diets which alone increase remarkably the total counts of bifidobacteria. In conclusion, distinct dietary effects on the faecal counts of Cl. perfringens and bifidobacteria with a clear antagonistic pattern were observed. The main factor was the protein source and level in the diet. In this case, NDO favoured the concentrations of bifidobacteria to a limited degree. Further studies are needed to evaluate time effects, metabolic consequences and the potential implication for health promotion in pets.     

TSE pathogenesis in cattle and sheep

Many studies have been undertaken in rodents to study the pathogenesis of transmissible spongiform encephalopathies (TSE). Only a few studies have focused on the pathogenesis of bovine spongiform encephalopathy (BSE) and scrapie in their natural hosts. In this review, we summarize the most recent insights into the pathogenesis of BSE and scrapie starting from the initial uptake of TSE agents and crossing of the gut epithelium. Following replication in the gut-associated lymphoid tissues (GALT), TSE agents spread to the enteric nervous system (ENS) of the gut. Infection is then carried through the efferent fibers of the post-ganglionic neurons of the parasympathetic and sympathetic nervous system to the pre-ganglionic neurons in the medulla oblongata of the brain and the thoracic segments of the spinal cord. The differences between the pathogenesis of BSE in cattle and scrapie in sheep are discussed as well as the possible existence of additional pathogenetic routes.     

水产动物益生菌研究进展

益生菌是指能够在生物体内存活,对宿主的生命健康有益的一类微生物。益生菌的应用是对水产养殖业现存问题十分有效的解决途径之一。目前已有报道的水产益生菌有乳酸菌属、双歧杆菌属、弧菌属、假单胞菌属、芽孢杆菌、硝化菌、光合菌等。乳酸菌、芽孢杆菌、酵母菌等已作为饵料添加剂应用于水产动物,起到很好的防治疾病和增进健康的作用;光合细菌对水质改良的作用十分显著,已在美国、东南亚等地得到广泛应用。益生菌制剂在将来很有可能成为抗生素的替代品,有着较好的发展前景。论文就其种类、作用机理、应用等方面做一简述。     

Follicle associated epithelium of the gut associated lymphoid tissue of cattle

The morphology of the gut-associated lymphoid tissue of the small and large intestine in three gnotobiotic calves was examined by scanning and transmission electron microscopy, and the distribution of specialized membranous cells present in the follicle associated epithelium was defined. Isolated follicles remaining in the ileum of a cow after involution of the continuous Peyer's patch were examined by scanning electron microscopy. The presence of membrane-bound particles, reported to be exclusively associated with the continuous Peyer's patch, was investigated in other gut-associated tissue of the small and large intestine of the calf. The presence of two types of follicle associated epithelium in the small intestine of the calf was confirmed, and the follicle associated epithelium of the large intestine proved to be a homogeneous population of specialized membranous cells, similar to that of the continuous Peyer's patch of the small intestine. In the discrete Peyer's patches, some specialized membranous cells were completely hidden by adjacent enterocytes and could only be identified by cytoplasmic extensions into the intestinal lumen. In the proximal part of the continuous Peyer's patch, a transitional zone was detected where the follicle associated epithelium of some doomed villi was composed of a homogeneous population of specialized membranous cells, while the epithelium covering other doomed villi consisted of a mixture of absorptive and specialized membranous cells, usually only found in the discrete Peyer's patches. Membrane-bound particles were observed associated with gut-associated lymphoid tissue in the small and large intestine.     

Interactions between commensal bacteria and the gut-associated immune system of the chicken

The chicken gut-associated lymphoid tissue is made up of a number of tissues and cells that are responsible for generating mucosal immune responses and maintaining intestinal homeostasis. The normal chicken microbiota also contributes to this via the ability to activate both innate defense mechanisms and adaptive immune responses. If left uncontrolled, immune activation in response to the normal microbiota would pose a risk of excessive inflammation and intestinal damage. Therefore, it is important that immune responses to the normal microbiota be under strict regulatory control. Through studies of mammals, it has been established that the mucosal immune system has specialized regulatory and anti-inflammatory mechanisms for eliminating or tolerating the normal microbiota. The mechanisms that exist in the chicken to control host responses to the normal microbiota, although assumed to be similar to that of mammals, have not yet been fully described. This review summarizes what is currently known about the host response to the intestinal microbiota, particularly in the chicken.