双歧杆菌的保健功能及其研究进展

Tissier于 1899年首次分离出双歧杆菌。近三十年来 ,人们对双歧杆菌的特性、分布、分类、营养意义等研究取得很大的进展。许多研究报道 ,双歧杆菌具有维护肠道生态平衡和促进人体健康的作用 ,是食品加工和保藏的著名菌种 ,广泛用于发酵奶、发酵奶饮料、黄奶油、酸奶、奶酪和婴儿食品等。双歧杆菌具有抗菌、防治肠道感染、增强免疫功能、抗肿瘤作用等多种生物学功能 ,有潜在预防和治疗疾病作用 ,在食品工业和药品开发领域具有广阔的前景 [1 ]。1　双歧杆菌的种类及分布双歧杆菌归属于放线菌科双歧杆菌属 ,专性厌氧 ,革兰阳性 ,呈杆状 ,不形…     

双歧因子的提取及其促双歧杆菌生长的初步观察

本文介绍了多种从猪胃粘蛋白及胡萝卜中提取双歧因子的方法。并用含双歧因子的培养基对四种双歧杆菌的生长进行了定性、定量观察,其结果显示了双歧因子是一种具有促双歧杆菌生长的活性因子,它可用于治疗某些疾病或作为保健食品及动物饲料添加剂,对促进人、动物体的健康及婴幼儿的正常发育具有重要生理意义。     

双歧杆菌对母乳低聚糖利用的研究进展

母乳低聚糖(human milk oligosaccharides,HMOs)是一类存在于人乳中复杂的混合低聚糖,是母乳中的重要成分,在婴幼儿生长发育中起到重要作用。母乳低聚糖可作为影响肠道微生物群组成的益生元,可选择性地促进母乳喂养婴儿肠道双歧杆菌的生长。婴儿肠道内相关的双歧杆菌具有糖苷酶和转运蛋白等分子工具,使其能够代谢HMOs,且代谢过程具有菌株特异性。本文对2′ 岩藻糖基乳糖、3′ 岩藻糖基乳糖、3′ 唾液酸乳糖、6′ 唾液酸乳糖、乳糖 N 四糖、乳糖 N 新四糖等常见HMOs的结构和特点进行总结,并讨论不同双歧杆菌对不同HMOs的利用特点和机制,为开发针对不同双歧杆菌的特异性益生元提供相应的理论指导。     

双歧杆菌胞外多糖研究进展

双歧杆菌是一种众所周知、使用范围很广的商用益生菌,其生长繁殖贯穿人的整个生命过程。有研究表明双歧杆菌具有益生功能的主要分子机制依赖于双歧杆菌自身分泌的胞外多糖。尽管一些细菌胞外多糖已经商业化用于食品和医药保健品等领域,如黄原胶、透明质酸和右旋糖苷等,但双歧杆菌等常用益生菌的胞外多糖还鲜见有商业化应用的报道。本文综述了双歧杆菌胞外多糖的合成分子机制、单糖组成及其理化性质,分析了双歧杆菌胞外多糖对肠道菌群的调节作用,阐述了双歧杆菌胞外多糖在抗氧化、改善和提高宿主免疫、抗过敏、抗肿瘤以及降低胆固醇等方面所体现出的益生功能。同时也对双歧杆菌胞外多糖分子机制研究和产业化开发方面存在的一些问题进行了讨论。     

婴儿肠道双歧杆菌多样性的研究进展

双歧杆菌是婴儿肠道中最丰富的微生物,对婴儿肠道微生物的成熟和稳定有显著影响,与婴儿健康紧密相关。大量研究表明,婴儿肠道中最广泛存在的双歧杆菌有长双歧杆菌、短双歧杆菌和两歧双歧杆菌。母婴之间垂直传递可直接影响婴儿肠道中双歧杆菌各种属的早期定植和相对丰度变化,特别是分娩方式和喂养方式会显著影响婴儿肠道双歧杆菌。此外,胎龄和辅食等因素对婴儿肠道中双歧杆菌的组成与多样性也有一定影响。本文对婴儿肠道双歧杆菌的种属组成、相对丰度变化以及影响其多样性的因素进行了综述,为婴儿双歧杆菌群落的认识提供一定的理论依据。     

一种含双歧杆菌种属特异性复制子的新型大肠杆菌-双歧杆菌穿梭质粒的构建

目前,双歧杆菌的转化是一个技术难题,与大肠杆菌等宿主菌的高转化效率不同,采用普通的原核质粒无法转化双歧杆菌.为此,本文提出双歧杆菌转化对质粒复制子具有"种属特异性"要求,并通过构建含有双歧杆菌特异复制子的新型穿梭质粒,以求解决这一难题.首先从GenBank获取长双歧杆菌隐性质粒pMB1的序列信息,采用Overlap-PCR方法获得其全长DNA,作为拟构建质粒的复制子;继而采用重组技术,将其与pMK4质粒片段(含大肠杆菌复制子pUC和抗氯霉素基因Cat)重组,构建大肠杆菌-双歧杆菌穿梭质粒;用电穿孔法将重组质粒转化双歧杆菌,通过观察不同电转参数下的转化效率,选择双歧杆菌转化的最佳条件.结果,成功获得全长1899bp的pMB1复制子并构建成功含有pMB1和pUC双复制子的原核重组质粒,经酶切和测序鉴定正确,命名为pCMB1.以重组质粒成功转化了长双歧杆菌NCC2705和NQ1501,而其它3种野生型双歧杆菌(包括1株长双歧杆菌)未能转化成功.结论:质粒中含有双歧杆菌种属特异的复制子是实现双歧杆菌转化的必要条件;即使是含有特异复制子的质粒也只能转化有限数量种型甚至有限数量种株的双歧杆菌;选择最佳电转化条件能显著提高转化效率.     

双歧杆菌质粒的检测及其对抗生素敏感性

本文应用ＬｅＢＬａｎｃ法提取６种２０株双歧杆菌菌株的质粒,发现共有４个种的６株菌株存在着１～３个质粒,多数质粒的分子量小于６．０ｋｂ。存在质粒的双歧杆菌包括分离自人的短双歧杆菌、青春双歧杆菌、两歧双岐杆菌和婴儿双歧杆菌。用固体培养基滤纸片抑菌圈法测定双歧杆菌对１５种常用抗生素的敏感性,结果表明,测试的２０株双歧杆菌菌株对所检测的１５种抗生素的敏感性无规律可循,而且质粒消除实验表明质粒的存在与所检测的抗生素抗性无相关性。     

金双歧治疗功能性便秘临床应用

“口服双歧杆菌、乳杆菌、嗜热链球菌三联活菌片”属于微生态制剂,临床上用于治疗肠道菌群失调引起的腹泻、慢性腹泻、抗生素治疗无效的腹泻及便秘。其药效成分是长双歧杆菌、保加利亚乳杆菌、嗜热链球菌3种健康人体肠道正常生理性细菌,可在人体肠道中生长繁殖。其药理作用是通过直接补充人体正常生理细菌,调整肠道菌群平衡,抑制并清除肠道中对人具有潜在危害的细菌,从而达到治疗腹泻及便秘的目的。“口服双歧杆菌、乳杆菌、嗜热链球菌三联活菌片”,商品名为金双歧。金双歧在临床上应用较为广泛,获得医护工作者及患者的一致好评。现将金双歧…     

由蛋白质介导的双歧杆菌对体外培养肠上皮细胞的粘附

本文对双歧杆菌和体外肠上皮细胞系Ｌｏｖｏ细胞间的粘附进行了研究。结果表明,双歧杆菌能特异性地粘附于肠上皮细胞周围,并且具有浓度和时间效应;各株双歧杆菌的粘附力存在着差异,新分离株高于标准株,胰蛋白酶处理耗尽培养液上清可完全抑制其粘附;高温也能降低粘附力;而白蛋白对粘附无影响。提示,双歧杆菌粘附素可能是一种不耐热的蛋白质,主要存在于耗尽培养液上清中     

应用TGGE技术分析人肠道中双歧杆菌的组成

用温度梯度凝胶电泳(TGGE)技术结合16SrDNA克隆、测序,对健康人肠道中双歧杆菌的组成进行了分析。10例健康人肠道双歧杆菌的TGGE分析显示:人肠道内双歧杆菌的组成具有宿主特异性,不同人肠道双歧杆菌种的多样性和种类不同。通过对一健康儿童肠道双歧杆菌属特异性PCR扩增产物的测序及TGGE电泳行为的分析发现,该个体双歧杆菌TGGE图谱中的条带分别代表Bifidobacteriumbifidum、B.infantis、B.longum、B.adolescentis、B.pseudocatenulatum等种和一新种,其中B.pseudocatenulatum(假小链双歧杆菌)是大多数个体共有且较优势的种类。用传统培养方法只检出B.pseudocatenulatum和B.longum两种。基于双歧杆菌属特异性PCR基础上的TGGE方法结合16SrDNA克隆文库分析可较灵敏、直观地反映人肠道中双歧杆菌的组成。     

丁酸梭菌在医学领域中的研究进展

肠道益生菌是定植于人体肠道内,能产生确切健康功效从而改善宿主微生态平衡,对宿主发挥有益作用的一类活性微生物总称。最近越来越多的研究表明肥胖、糖尿病、肠易激综合征、骨质疏松等与肠道菌群密切相关,而丁酸梭菌由于能够促进其他有益菌（乳杆菌、双歧杆菌）生长,具有其他有益生菌没有的特性,受到越来越多研究者的重视。本文通过综述近几年有关丁酸梭菌与神经、内分泌、消化等系统中部分疾病的关系,总结了丁酸梭菌可能具有的治疗机制,并将其与益生菌在治疗骨质疏松症时所发挥的机制进行对比,以展望丁酸梭菌可能具有治疗骨质疏松的潜力。     

基于CNKI和PubMed数据库的双歧杆菌研究文献分析

目的 统计分析国内外已发表的与双歧杆菌相关的期刊文献,了解其中的研究热点与发展趋势,为相关科研工作者提供参考。方法 研究资料来源于CNKI和PubMed数据库,应用文献计量学的方法对两个数据库所收录的双歧杆菌相关文献进行分析。结果 截至2018年8月15日,CNKI和PubMed分别收录了9277和5130篇相关文献。在数量上,国内外对双歧杆菌的研究都从20世纪90年代开始快速增长。从学科分布和关键词来看,中外研究共同关注了消化道疾病和儿科学,同时中外研究侧重点又有明显的差异。国内研究机构参与发表在国际杂志上的文章数量较多,但是其中作为第一发表单位的文章数量偏少。结论 双歧杆菌相关的基础与应用研究还有许多需要深入和拓展的方面,研究者应当在相关领域进行实质性突破。     

地衣芽胞杆菌在消化系统疾病中的应用

地衣芽胞杆菌在土壤等环境中普遍存在,体外研究显示该菌株的代谢产物可对致病菌的生长产生抑制作用。地衣芽胞杆菌活菌制剂进入肠道后可产生多种抗菌物质,并可通过生物夺氧作用改善肠道内环境,具有调节肠道微生态,改善消化道屏障功能,减轻炎症反应,增强免疫功能等作用,在肠道菌群失调相关疾病中应用前景广阔。地衣芽胞杆菌活菌制剂已广泛应用于腹泻疾病的治疗,并在炎症性肠病、某些肝病及幽门螺杆菌根除等治疗的研究中显示出其在改善肠道内环境,促进病情缓解的疗效。本文将对地衣芽胞杆菌活菌制剂及其消化系统疾病中的应用进行简要的叙述,并对该益生菌的研究方向做初步的探讨。     

Distribution of bifidobacteria in the gastrointestinal tract of calves

Development of gastrointestinal microflora of calves with special reference to bifidobacteria was investigated; fecal bacteria were enumerated in calves aged 3 days to 7 weeks. Bacteria were detected by using selective media, bifidobacteria using modified TPY agar with an addition of mupirocin and acetic acid and by fluorescence in situ hybridization (FISH). Bifidobacteria were dominant group of fecal flora of calves after 7 d of life, constituting 10 % of total bacterial counts. The highest bacterial concentrations were observed in rumen, cecum, and colon, the lowest in abomasum and duodenum. Bifidobacteria and lactobacilli exhibited the highest survival ability during stomach passage and dominated in all parts of the digestive tract. Bifidobacteria counts determined by FISH were significantly higher than those provided by cultivation. Modified TPY agar was highly selective and suitable for bifidobacteria isolation but FISH was shown to be a more precise method for their enumeration. Our results show that gastrointestinal microflora of calves in the milk-feeding period is similar to breast-fed infants with respect to the occurrence of bifidobacteria as a dominant bacterial group. The use of Bifidobacterium strains offers a promising way for providing beneficial effectors for calves in the milk-feeding period.     

阿莫西林干预对婴儿优势菌在无菌小鼠体内定植的影响

目的 考察阿莫西林干预对婴儿优势菌双歧杆菌及乳杆菌在无菌小鼠体内定植的影响。方法 1日龄Balb/c无菌乳鼠接种婴儿粪便悬液。饲养至7~21日龄灌胃阿莫西林（100 mg/kg）,对照组在同日龄给予等体积的生理盐水。利用qRT-PCR检测小鼠粪便中双歧杆菌、乳杆菌的含量。结果 阿莫西林处理可显著降低乳杆菌（P0.05）。结论 哺乳期阿莫西林干预会导致乳杆菌、双歧杆菌在小鼠体内定植量下降,但停药后小鼠饲养至成年二者可达到正常定植量,婴儿菌群定植小鼠模型可以模拟与现有动物模型一致的阿莫西林对双歧杆菌、乳杆菌定植的影响规律。     

脑梗死患者肠道菌群特征及其与血清代谢标志物水平的相关性

目的 探究脑梗死患者肠道菌群特征,分析其与血清代谢标志物水平的相关性。方法 对2018年1月至2018年8月间于我院就诊的43例急性脑梗死患者（脑梗死组）和43例健康体检者（对照组）的肠道菌群特征进行检测,采用16S rDNA实时荧光定量PCR技术对两组患者肠道菌群进行测定、分析,并对两组患者血清代谢标志物（血肌酐、尿素氮、总胆固醇、甘油三酯、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇、空腹血糖、糖化血红蛋白及超敏C反应蛋白）水平进行比较,应用Pearson相关系数模型探究患者肠道菌群特征与常用血清代谢标志物水平的相关性。结果 脑梗死组患者的空腹血糖、HbA1c、TC、TG、LDL-C和hs-CRP水平显著高于对照组,HDL-C水平显著低于对照组（Ps<0.05）。16S rDNA分析结果显示,兼性厌氧菌是肠道的主要菌群,专性厌氧菌其次,需氧菌的比例最小。脑梗死组患者肠道主要优势菌为链球菌、大肠埃希菌和葡萄球菌,而对照组患者为双歧杆菌、乳杆菌等。脑梗死组患者肠道艰难梭菌、肠球菌、链球菌和葡萄球菌水平明显高于对照组（Ps<0.05）,双歧杆菌、奇异菌和乳杆菌水平明显低于对照组（Ps<0.05）。Pearson相关性分析显示,奇异菌和罗伊乳杆菌水平与HbA1c水平呈明显负相关（r=－0.225,－0.348,Ps<0.05）,植物乳杆菌数量与TC水平呈明显负相关（r=－0.177,P=0.019）,双歧杆菌与TG和LDL-C水平呈明显负相关（r=－0.214,－0.305,Ps<0.05）,艰难梭菌和葡萄球菌分别与LDL-C和hs-CRP呈明显正相关（r=0.375,0.213,Ps<0.05）。结论 脑梗死患者与健康人群肠道菌群存在明显差异,其中双歧杆菌、乳杆菌及奇异菌水平与糖、脂代谢指标呈负相关,艰难梭菌和葡萄球菌与低密度脂蛋白胆固醇和超敏C反应蛋白呈明显正相关。     

An optimized enumeration method for sorbitol-fermenting Bifidobacteria in water samples

With increased focus on watershed protection under the Surface Water Treatment Rule, indicators that discriminate among sources of microbial inputs (microbial source tracking) are needed to supplement the quantitative information provided by total and fecal coliform measurements for drinking water monitoring. Bifidobacteria are found in the digestive tract and feces of humans and other animals, and also in sewage. Sorbitol is a food additive used exclusively in food intended for human consumption. Therefore, the presence of sorbitol-fermenting Bifidobacteria in environmental waters can be indicative of sources of human fecal contamination. A series of media were evaluated using ATCC cultures of B. breve and B. adolescentis, feces from different animals, and domestic wastewater samples. The media evaluated were Human Bifid Sorbitol agar (HBSA), modified Human Bifid Sorbitol agar, Beerens Medium, modified Beerens Medium, Reinforced Clostridial agar, BIM-25 Medium, and modified BIM-25 Medium. Variables such as sample preservation, incubation time, different pH indicators, plating technique, and discontinuous exposure to sorbitol were also evaluated. A series of biochemical tests were used to confirm positive colonies enumerated on the various media. Membrane filtration and enumeration of sodium sulfite preserved samples on HBSA containing bromocresol purple using loose lidded plates for 48 h provided the best recoveries for presumptive positive colonies. A number of sorbitol-fermenters that were not Bifidobacteria were able to grow on all media tested, resulting in false-positives. Therefore, plating on HBSA should be followed by a confirmation step when monitoring for sorbitol-fermenting Bifidobacteria in environmental waters. A year-long sampling survey of a managed reservoir in Massachusetts provided field validation of the proposed methodology for sorbitol-fermenting Bifidobacteria as a human-related source tracking indicator tool.     

Bifidobacteria in the digestive tract of bumblebees

Bifidobacteria and other bacterial groups (lactobacilli, facultative anaerobes, anaerobes) from the digestive tract of three bumblebee species (Bombus lucorum (34 samples), Bombus pascuorum (18 samples) and Bombus lapidarius (9 samples)) were enumerated and characterised. Counts of facultative anaerobic bacteria and lactobacilli (5.41 ± 2.92 and 2.69 ± 3.02 log CFU/g of digestive tract content) were lower than those of anaerobes (7.66 ± 0.86 log CFU/g). Counts of bifidobacteria were determined using two selective media: MTPY (Modified Trypticase Phytone Yeast extract agar) and a new medium with pollen extract. There was no significant difference between the counts of bifidobacteria from both media, 5.00 ± 2.92 log CFU/g on MTPY and 5.00 ± 2.87 on the pollen medium. Subsequently, 187 bacterial strains of the family Bifidobacteriaceae (fructose-6-phosphate phosphoketolase-positive) were isolated from three different localities and from all three species of bumblebees. Bifidobacteria were found in 42 out of 61 specimens (69%). Twenty-three (38%) specimens had counts of bifidobacteria higher than 7.0 log CFU/g. Bifidobacteria represented the dominant group of anaerobes (>70% of total anaerobes), i.e., the principal group of bacteria in the bumblebee digestive tract, in only fourteen specimens (23% of total). For the first time, bifidobacteria were isolated from the digestive tract of bumblebees. In addition, we suggest, on the basis of biochemical tests (API 50 CHL and RAPID ID 32) and genetic methods (PCR and DGGE), that these bacteria may represent new species within the family of Bifidobacteriaceae.     

结肠癌患者肠道菌群变化的临床研究

目的 对比分析结肠癌患者肠道菌群数量变化的特点,为结肠癌的治疗提供新途径。方法 选取2014年6月至2015年6月在本院就诊的结肠癌患者48例为试验组,同期在本院体检的48例健康者为对照组。取两组患者粪便标本进行传统菌落培养与计数检测,同时采用荧光定量聚合酶链反应（qPCR）法检测肠道细菌相对含量与相关基因表达拷贝数。结果 菌落计数结果显示试验组大肠埃希菌、屎肠球菌和酵母菌数量多于对照组,而双歧杆菌和乳酸杆菌数量少于对照组,组间比较差异均有统计学意义（P0.05）。结论 结肠癌患者大肠埃希菌、屎肠球菌和酵母菌数量明显增加,双歧杆菌和乳酸杆菌数量明显减少,肠道菌群数量变化在结肠癌的发生和发展中可能发挥一定作用。     

Modelling the effect of birth and feeding modes on the development of human gut microbiota

The human gut microbiota is transmitted from mother to infant through vaginal birth and breastfeeding. Bifidobacterium, a genus that dominates the infants’ gut, is adapted to breast milk in its ability to metabolize human milk oligosaccharides; it is regarded as a mutualist owing to its involvement in the development of the immune system. The composition of microbiota, including the abundance of Bifidobacteria, is highly variable between individuals and some microbial profiles are associated with diseases. However, whether and how birth and feeding practices contribute to such variation remains unclear. To understand how early events affect the establishment of microbiota, we develop a mathematical model of two types of Bifidobacteria and a generic compartment of commensal competitors. We show how early events affect competition between mutualists and commensals and microbe-host-immune interactions to cause long-term alterations in gut microbial profiles. Bifidobacteria associated with breast milk can trigger immune responses with lasting effects on the microbial community structure. Our model shows that, in response to a change in birth environment, competition alone can produce two distinct microbial profiles post-weaning. Adding immune regulation to our competition model allows for variations in microbial profiles in response to different feeding practices. This analysis highlights the importance of microbe–microbe and microbe–host interactions in shaping the gut populations following different birth and feeding modes.