An Overview: The Toxicity of Ageratina adenophora on Animals and Its Possible Interventions

Ageratina adenophora is one of the major invasive weeds that causes instability of the ecosystem. Research has reported that A. adenophora produces allelochemicals that inhibit the growth and development of food crops, and also contain some toxic compounds that cause toxicity to animals that consume it. Over the past decades, studies on the identification of major toxic compounds of A. adenophora and their toxic molecular mechanisms have been reported. In addition, weed control interventions, such as herbicides application, was employed to reduce the spread of A. adenophora. However, the development of therapeutic and prophylactic measures to treat the various A. adenophora—induced toxicities, such as hepatotoxicity, splenotoxicity and other related disorders, have not been established to date. The main toxic pathogenesis of A. adenophora is oxidative stress and inflammation. However, numerous studies have verified that some extracts and secondary metabolites isolated from A. adenophora possess anti-oxidation and anti-inflammation activities, which implies that these extracts can relieve toxicity and aid in the development of drug or feed supplements to treat poisoning-related disorders caused by A. adenophora. Furthermore, beneficial bacteria isolated from rumen microbes and A. adenophora can degrade major toxic compounds in A. adenophora so as to be developed into microbial feed additives to help ameliorate toxicity mediated by A. adenophora. This review presents an overview of the toxic mechanisms of A. adenophora, provides possible therapeutic strategies that are available to mitigate the toxicity of A. adenophora and introduces relevant information on identifying novel prophylactic and therapeutic measures against A. adenophora—induced toxicity.     

益生菌在我国保健食品中的应用进展

由于益生菌类原料在调节肠道菌群和增强免疫力保健功能的研究比较系统,健康功效明确,因此,其在保健食品中应用越来越广泛,而且部分菌株已被国家市场监督管理总局明文规定允许用于婴幼儿食品的开发.随着科学技术的快速发展以及相关研究的不断深入,益生菌类原料具有的其它保健功能不断被发掘,而且作用机理也不断明晰,这为其在保健食品行业的...     

乳酸菌R8高密度培养的发酵工艺研究

以乳杆菌R8菌株为材料,对其高密度发酵培养工艺进行了研究。以菌体密度(OD600)及碳源(葡萄糖)的利用情况为主要参考指标,研究了中和剂、pH、接种量、初始糖含量、通气方式以及补料工艺等对菌体在发酵罐内生长的影响,并对试验菌进行250 L中试放大工艺的优化。优化菌体小试发酵工艺为:将种子液以8%(V/V)的接种量接种于装液量70%的小罐,初糖浓度40 g/L,搅拌转速100 r/min,间歇通氮气维持一定的厌氧环境,自动流加12.5%的氨水控制pH恒定在5.8,37℃恒温发酵。250 L中试发酵工艺为:将控制pH 5.8,37℃恒温发酵7 h左右的种子液以8%接种量接种于装液量为70%的250 L发酵罐,搅拌转速60 r/min,自动流加氨水控制pH 5.8,间歇通氮气不保压(每2 h以0.2 vvm的速率通氮气5 min),37℃恒温发酵10 h左右结束。250 L规模所得发酵液的活菌浓度约为8×109 CFU/mL,经真空冷冻干燥所得的菌粉活菌浓度约为1.2×1011 CFU/g。     

浅谈肠道益生菌在食品中的安全性问题

近年来益生菌食品发展迅速,其产品类型及品种日益丰富,但目前其产业还处于发展阶段。益生菌的安全性和功能性评价体系不够完善,质量检验方法有待改进。本文综述了食品中肠道益生菌的分类、鉴定,益生菌的代谢产物,储存条件,益生菌剂量水平与使用时间,益生菌对抗生素的耐受性及感染能力及对人体安全性影响,且举例说明了目前市场上的益生菌产品可能带来的问题,以期为食品中肠道益生菌的研究、检验、监测提供理论参考。     

不同发酵方式的益生菌酸奶代谢组学的应用及探究

本文在分析了常用的微生物代谢组学研究方法的基础上,采用UPLC-Q-TOF MS~E代谢组学技术结合主成分分析(PCA)和正交偏最小二乘判别分析(OPLS-DA)对不同发酵方式生产的益生菌酸奶进行了代谢组学的研究。结果表明,采用单一益生菌L.Plantarum P-8发酵得到的样品(p)和采用益生菌L.Plantarum P-8与传统酸奶发酵剂YC-X11共同发酵得到的样品(bp)在BPI基峰图存在较大差异,说明其代谢产物具有明显的不同。同时,采用UPLC-Q-TOF MS~E的分析方法共鉴定亮氨酸、甲硫氨酸、苯丙氨酸、色氨酸、4-羟基苯乳酸、泛酸、4-吡哆酸、L-肉毒碱、2-羟基-2-甲基琥珀酸、组氨醇、Asp-Pro-Pro、Met-Ser-OH、L-prolyl-L-Proline、Ala-Ala-Ile-Trp、His-His、Ala-Gly-Asn-Asn、Asp-Met-Met-Gln、Ala-Glu-Pro-Cys和Tyr-Asp等38个代谢物,并具体分析出了两种发酵方式得到的代谢产物的变化,为益生菌酸奶中代谢组学的应用提供新的思路。     

益生菌在喷雾干燥过程中的活性变化与保护策略

肠道菌群对于人体健康具有重要影响。口服足量的活性益生菌,有助于缓解急慢性肠炎、治疗腹泄、改善消化,已在临床治疗中得到一定应用。在食品市场上,益生菌干粉制剂亟需一种生产成本低、制粉简便的生产方法。喷雾干燥的生产能力强、制粉快速,但干燥过程中,雾化液滴经历一个快速升温与脱水过程,对其中的益生菌带来热胁迫、脱水胁迫、氧化胁迫等多种不利因素,造成菌体活性的大量损失。而喷雾干燥塔的结构,使塔内的液滴干燥过程难以追踪,不利于研究益生菌的失活历程以及探索益生菌与载体材料间的相互作用。本文从雾化液滴在干燥塔内的干燥历程着眼,回顾了益生菌活性随液滴干燥动力学变化的趋势,讨论了益生菌在喷雾干燥中经受的亚细胞结构损伤与功能性损伤,并系统总结了目前文献中报道的提升干燥后益生菌活性的主要方法,包括提升菌体耐受性、优化喷雾干燥条件和采用合适的保护性载体,并着重阐述了载体材料与益生菌细胞间的相互作用关系以及干燥历程的重要影响。文章指出为最大程度上保存喷雾干燥粉末中益生菌的活性,应综合微生物、干燥过程与食品化学（材料学）等领域的保护策略,设计一体化统合生产方案。依据微生物-保护载体间的相互作用设计高效保护配方载体,研发统合从微生物细胞培养至粉末储藏的新型生产工艺,是实验室及工业中合理设计工业级喷雾干燥过程、大量生产高活性益生菌制剂的关键。     

具有α-葡萄糖苷酶抑制作用益生菌的筛选及特性分析

以实验室77 株益生菌为研究对象,从其菌体细胞代谢物（cell-free excretory supernatants,CFS）和细胞内容物（cell-free extracts,CFE）两方面分析菌株对α-葡萄糖苷酶的抑制活性;同时还从耐酸性、细胞黏附性等方面对具有α-葡萄糖苷酶抑制活性的菌株进行了益生特性评价;最后利用主成分分析进行综合性评价,以期筛选出具有α-葡萄糖苷酶抑制作用的益生菌。结果表明,77?株益生菌的CFE对α-葡萄糖苷酶没有抑制作用;而CFS对α-葡萄糖苷酶具有一定的抑制作用,抑制率为2.53%～15.76%。选取抑制率明显高于其他益生菌（编号为ST-2、1.1881、GS-3和BLP12）菌株进行益生特性的研究。其中ST-2表现出很高的耐酸性和细胞黏附性;GS-3在模拟消化液中有很强的耐受性等,各菌株特性不一。主成分分析表明菌株BLP12的综合性能最好：其对α-葡萄糖苷酶的抑制率可达15.10%;于pH?2.0孵育3?h后,存活率能达到71.04%;于2.0%的胆盐条件下孵育24?h,存活率为0.70%;依次经模拟唾液、胃液、肠液消化后,存活率仍能达到88.27%,但对HT-29细胞的黏附率较低,仅为1.93%,总体上菌株BLP12对体外模拟胃肠环境的适应性很强。该菌株经过16S基因序列鉴定为植物乳杆菌,可作为降糖益生菌株应用于降糖食品的开发。     

Bifidobacterium bifidum YIT 10347 fermented milk exerts beneficial effects on gastrointestinal discomfort and symptoms in healthy adults: A double-blind,randomized, placebo-controlled study

In a preliminary open-label trial by our group, Bifidobacterium bifidum YIT 10347 (YIT10347) relieved gastric symptoms in patients with functional gastrointestinal disorders. Hence, in this study, we investigated the effects of YIT10347 on gastrointestinal symptoms in healthy adults. In this prospective double-blind, randomized, placebo-controlled trial (UMIN000024654), 100 healthy Japanese adults were randomly assigned to a YIT10347 group or placebo group and consumed 100 mL of YIT10347-fermented milk or placebo fermented milk, respectively, every day for 4 wk. Gastrointestinal symptoms were evaluated by using the modified Frequency Scale for Symptoms of Gastroesophageal Reflux Disease (m-FSSG) and Gastrointestinal Symptom Rating Scale (GSRS) as primary endpoints. Mental symptoms, quality of life, salivary stress markers, and gastric emptying were evaluated as secondary endpoints. Effectiveness and safety were analyzed in a per-protocol set (YIT10347 group, n = 39; placebo group, n = 40) and full analysis set (YIT10347 group, n = 50; placebo group, n = 50), respectively. In the m-FSSG evaluation, the YIT10347 group had a significantly higher relief rate of postprandial discomfort and greater changes in postprandial epigastric pain score from baseline than the placebo group. In the GSRS evaluation, the YIT10347 group had significantly higher relief rates of overall gastrointestinal symptoms, upper gastrointestinal symptoms, flatus, and diarrhea than the placebo group. We detected no significant differences in scores or relief rates of mental symptoms and quality of life, a salivary stress marker, or gastric emptying between the 2 groups. No severe adverse events associated with test beverage consumption were observed in either group. These findings suggest that daily consumption of YIT10347-fermented milk exerts beneficial effects on gastrointestinal discomfort and symptoms such as postprandial discomfort and epigastric pain in healthy adults.     

母乳及婴儿粪便菌群分析及功能菌株筛选

目的 探究母乳喂养婴儿粪便菌群及母乳菌群相关性,获得具有潜在益生功能菌株.方法 对健康母子母乳及婴儿粪便样本进行Illumina高通量测序,探究母乳与婴儿粪便样本菌群结构组成,母乳菌群在婴儿肠道垂直传递情况.通过体外益生性质研究,对分离的菌株进行筛选.结果 母乳中的主要菌科为肠杆菌科、莫拉氏菌科、葡萄球菌科和链球菌科;...     

Quality,functionality, and shelf life of fermented meat and meat products: A review

Fermentation of meat is a traditional preservation method used widely for improving quality and shelf life of fermented meat products. Fermentation of meat causes a number of physical, biochemical, and microbial changes, which eventually impart functional properties, sensory characteristics, and nutritional aspects to these products and inhibit the growth of various pathogenic and spoilage microorganisms. These changes include acidification (carbohydrate catabolism), solubilization and gelation of myofibrillar and sarcoplasmic proteins of muscle, degradation of proteins and lipids, reduction of nitrate into nitrite, formation of nitrosomyoglobin, and dehydration. Dry-fermented sausages are increasingly being used as carrier of probiotics. The production of biogenic amines during fermentation can be controlled by selecting proper starter cultures and other preventive measures such as quality of raw materials, hygienic measures, temperature, etc.