益生菌的安全性及基因改造

本文综述了益生菌的生理功能及其应具备的条件，从菌株筛选和耐药性角度探讨了益生菌的安全性及其安全使用时应考虑的因素，介绍了基因工程在作用机理研究、改善制品风味、提高功能特性及降低副反应等方面的应用及基因组学在益生菌研究中的作用．对现代遗传技术在扩大益生菌使用范围方面进行了。展望，为新型益生菌产品的开发和更广泛的应用提供了一定的应用参考。     

益生菌制剂及其发酵性乳制品

综述了益生菌的概念和益生菌菌株的选择标准、国外益生菌产品的发展状况、益生菌作为新型酸奶发酵剂的使用情况，以及益生酸奶的生产与消费情况。     

益生菌发酵乳功能研究进展

本文对益生菌发酵乳功能研究进展以及益生菌发酵乳产业化进展进行阐述,介绍益生菌发酵乳在降血糖、降血压、免疫活性、肠道疾病等方面的功能作用,为新型益生菌发酵乳的开发提供了参考依据。     

益生菌在功能食品中的应用研究

作为一种生理菌群,益生菌对人体肠道有诸多益处,对高血压、糖尿病、高血脂以及癌症等多种疾病都有预防作用。同时,益生菌还具有良好的营养保健功能,因而被人们广泛应用于食品领域中,如功能性食品、食品添加剂等,深受广大消费者的喜爱。基于此,本文阐述了益生菌的定义和种类,分析了益生菌的营养保健作用,包括抑制病原菌生长和繁殖,优化肠道菌群结构;提高机体免疫力,刺激免疫应答;降低肿瘤发病率,抑制癌细胞生长;延缓机体衰老,清除机体自由基;改善机体的血脂情况,降低胆固醇含量等,并对益生菌在功能食品中的应用进行了论述,希望能进一步拓展益生菌的应用范围。     

世界益生菌安全性评价方法

随着益生菌产业的不断发展壮大和研究的不断深入,益生菌的安全性受到越来越多的关注.然而,我国在益生菌安全性标准方面还比较滞后,极大地限制了产业的发展,同时也产生了一定的安全风险.此外,消费者对于益生菌产品消费显得信心不足.本文从益生菌可能产生的潜在危害出发,对世界各国益生菌体内和体外两个方面的安全性评价方法进行了整理和总结,以期对我国未来益生菌研究和益生菌产业发展提供参考.     

益生菌的生理功能及其安全性

在近十年来,益生菌的研究在全球范围内已经形成热潮,本文详细介绍了益生菌的生理功能以及其安全性.     

益生菌的安全性评价

过去几十年，益生菌被广泛应用于食品和医药等领域.选择和应用益生菌时，不仅要考虑益生菌的功能特性，安全性也是必须要考虑的方面.随着科学的不断发展，对益生菌的安全性认识也在发生变化，传统益生菌的安全性需要重新评价，新的益生菌菌种也不断地开发， 这些新菌种在使用前也应进行安全性评价.目前我国需要完善对这些新菌种进行系统的安全性评价的程序.本文综述了益生菌潜在的危险因素、转基因益生菌的安全性，安全性评价程序和国外如美国、欧盟、德国等国对益生菌的评价体系。     

益生菌的筛选及安全性研究进展

评价益生菌安全性的方法很多,如研究益生菌的特性、益生菌的药物动力学及益生菌与宿主之间的相互作用等。随着研究的不断深入,益生菌独特的营养与保健作用越来越受到人们广泛关注。就益生菌的筛选鉴定,生物安全性以及功能的最新研究进展作一综述。     

新型益生菌发酵乳制品的研究与开发

人在生长发育过程中,体内的微生物菌群往往需要由宿主摄入益生菌来调节改善菌群平衡,以便能够更好地保障自身的身体健康.我国不少大学已经开始成立课题组,对益生菌发酵乳制品的开发进行了研究,从目前来看,研究内容相对较多,我们也根据他们的研究问题,对新型益生菌发酵乳制品的研究与开发进行简要探讨.     

提高乳品中益生菌存活力的方法

从选择耐酸和耐胆汁的菌珠、合适的包装容器、合适的接种量，采取二步发酵法、微胶囊技术、添加蛋白质，肽和氨基酸、抗坏血酸、半胱氨酸及利用超声波降解乳酸菌释放β－半乳糖酶等10个方面，探讨了提高乳品中益生菌存活力的方法。     

Metabolic and biochemical responses of probiotic bacteria to oxygen

The interaction between oxygen and probiotic bacteria was studied by growing Lactobacillus acidophilus and Bifidobacterium spp. in 0, 5, 10, 15, and 21% oxygen in a hypoxic glove box. The metabolic responses of each probiotic strain in the different oxygen environments were monitored by measuring the levels of lactic acid and determining the lactate-to-acetate ratio. Biochemical changes induced by oxygen were examined by monitoring the specific activities of NADH oxidase, NADH peroxidase, and superoxide dismutase. In addition, the ability to decompose hydrogen peroxide and the sensitivity of each strain to hydrogen peroxide was also determined. With an increase in oxygen percentage, levels of lactic acid in L. acidophilus strains decreased, whereas the lactate-to-acetate ratio reduced in all the bifidobacteria tested. At 21% oxygen, the specific activities of NADH oxidase and NADH peroxidase, and the hydrogen peroxide decomposing ability of five probiotic strains was significantly higher than at 0% oxygen. The sensitivity of the probiotic strains to hydrogen peroxide however, remained unaffected in all the different oxygen percentages. Superoxide dismutase levels did not reveal any conclusive trend. In both L. acidophilus and Bifidobacterium spp., NADH oxidase and NADH peroxidase functioned optimally at pH 5. Growth in the various oxygen environments did not change this optimum pH.     

Interactions among lactic acid starter and probiotic bacteria used for fermented dairy products

Interactions among lactic acid starter and probiotic bacteria were investigated to establish adequate combinations of strains to manufacture probiotic dairy products. For this aim, a total of 48 strains of Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, Lactococcus lactis, Lactobacillus acidophilus, Lactobacillus casei, and Bifidobacterium spp. (eight of each) were used. The detection of bacterial interactions was carried out using the well-diffusion agar assay, and the interactions found were further characterized by growth kinetics. A variety of interactions was demonstrated. Lb. delbrueckii subsp. bulgaricus was found to be able to inhibit S. thermophilus strains. Among probiotic cultures, Lb. acidophilus was the sole species that was inhibited by the others (Lb. casei and Bifidobacterium). In general, probiotic bacteria proved to be more inhibitory towards lactic acid bacteria than vice versa since the latter did not exert any effect on the growth of the former, with some exceptions. The study of interactions by growth kinetics allowed the setting of four different kinds of behaviors between species of lactic acid starter and probiotic bacteria (stimulation, delay, complete inhibition of growth, and no effects among them). The possible interactions among the strains selected to manufacture a probiotic fermented dairy product should be taken into account when choosing the best combination/s to optimize their performance in the process and their survival in the products during cold storage.     

Binding of aflatoxin B1 by probiotic bacteria

The ability of six probiotic bacteria to bind a common food carcinogen, aflatoxin B₁, was assessed. The studied strains included Lactobacillus strains and one Bifidobacterium strain. The strains were incubated in vitro with alfatoxin B₁ and the toxin residue in the supernatant was measured using high‐performance liquid chromatography. The aflatoxin‐binding capacity of the strains was found to range from 5.8 to 31.3%. The results further support the observation that a number of probiotic bacteria are able to bind specific dietary contaminants. Although the extent of binding varies depending on the bacterial strain used, the data may explain some of the antimutagenic and anticarcinogenic effects of probiotic micro‐organisms. © 2000 Society of Chemical Industry     

分离自藏灵菇的乳酸菌的益生特性

从藏灵菇中分离纯化5株乳酸菌,初步鉴定2株为嗜酸乳杆菌,3株为乳酸乳球菌。选取其中2株菌研究其益生特性。结果表明,从藏灵菇中分离出的乳酸菌具有良好的益生特性,2株乳酸菌在pH值为4～6可生长良好;耐热范围为30～60℃;胆盐耐受性为0.1%～0.5%;发酵液对金黄色葡萄球菌、沙门氏菌、大肠杆菌等肠道病原菌有抑制作用;对抗生素有不同程度的耐药性。     

Safety assessment of the human milk-isolated probiotic Lactobacillus salivarius CECT5713

The potential probiotic bacteria Lactobacillus salivarius CECT5713 has recently been isolated from human milk and characterized. The objective of the present study was to evaluate the oral toxicity of this potential probiotic bacteria in mice. With this aim, 50 Balb/C mice were divided in 5 groups (n = 10). Three of these groups were treated orally with different doses of L. salivarius CECT5713: 5 × 10⁸, 2 × 10⁹, or 10¹⁰ cfu/mouse per d for 28 d. One additional group was administered the vehicle alone and was used as a control. The last group were injected intraperitoneally with 10⁸ cfu/mouse in a single dose and killed 2 (n = 5) and 5 (n = 5) d after intraperitoneal injection. Food intake, body weight, bacterial translocation, serum α-amyloid protein, and different biochemical parameters were analyzed. Oral administration of L. salivarius CECT5713 to mice had no adverse effects on mouse body weight or food intake. No bacteremia was shown and there was no treatment-associated bacterial translocation to the liver or spleen. Intraperitoneal administration caused a significant bacterial translocation to the liver and spleen, but not to the blood. However, this translocation was not related to illness or death at either d 2 or d 5, although an increase in plasma serum α-amyloid protein was observed at d 2. These results suggest that the strain L. salivarius CECT5713 is nonpathogenic for mice, even in doses 10,000 times higher (expressed per kilograms of body weight) than those normally consumed by humans. Thus, this strain is likely to be safe for human consumption.     

乳酸菌的益生功能及作用机制研究进展

乳酸菌类益生菌是功能性食品的主要生理活性成分之一,其益生作用已经成为食品科学和临床医学领域的研究热点。本文就近年来乳酸菌改善乳糖不耐症、防治腹泻和消化性溃疡、提高机体免疫力等益生功能和作用机制的研究进展做一综述,并对研究前景提出展望,以期为我国乳酸菌的开发应用奠定基础。      

潜在益生乳酸菌分离和鉴定研究进展

利用益生菌提高人类健康水平是当前营养健康领域最具前景的方向之一。乳酸菌是食品中常用的益生菌,迄今为止,联合国粮食及农业组织（FAO）和世界卫生组织（WHO）推荐仅从人的胃肠道分离的乳酸菌可在食品中使用。而越来越多的研究从食品来源中分离出具有益生功能的菌株以扩大益生菌的选择范围。随着分子生物学和检测分析等技术的发展,基质辅助激光解吸电离-飞行时间质谱（MALDI-TOF MS）、全基因组测序、实时荧光定量聚合酶链式反应（RT-FQ-PCR）等技术可以鉴定到亚种及菌株水平上的益生菌。鉴于分离鉴定技术是益生菌安全规范应用的先决条件,该文综述了近年来针对潜在益生乳酸菌有效分离和鉴定技术的研究进展,以期为我国益生乳酸菌自主开发利用提供借鉴。     

日本益生菌、益生元市场与应用概况

为了大力推广益生菌和益生元,介绍了日本益生菌制品、益生元、灭活细胞粉及对它们的管理情况。其中,日本厚生劳动省批准了65种特定保健食品,允许使用了近20种菌株．同时,各种功能性低聚糖已广泛使用在400多种食品、保健食品以及宠物饲料中,并说明了除益生菌活菌体外,益生菌或肠道正常菌群的灭活细胞,在大量存在下也可和活菌体一样具有免疫增强作用和发挥益生元的功能的作用。