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【名称】乳糖耐受试验和氢呼吸试验【英文名】lactose tolerance test and hydrogen breath test【别名】【概述】乳糖不耐受常见于婴儿，表现为腹泻、吐奶、生长迟滞、吸收障碍。
当给予去乳糖饮食时，患儿临床症状消失。
这种综合征是由于患儿肠道中糖分解酶(乳糖酶)缺乏所引起的。
乳糖耐受试验实际上是利用GTT试验来诊断肠道双糖酶(乳糖酶)缺乏。
测试葡萄糖，观察其在检测个体空腹样本中水平升高或不升高。
氢呼吸试验是检测呼气样本中氢的水平，氢的水平升高是由肠道中乳糖积聚引起的。
结肠细菌代谢乳糖而生成氢气。
【原理】【试剂】【操作方法】实验步骤。
1.遵守GTT操作指示。
2.空腹时抽取血样之后，患者口服200ml含50g乳糖的水溶液(2g乳糖/kg)。
3.间隔O、30min、60min、90min采集血样以备测乳糖水平。
4.血样采集的同时，采集呼气样本以便做氢呼吸试验。
联系实验室，咨询采集标本相关的注意事项。
【正常值】葡萄糖水平从正常值变化为：＞1.7mmol/L(＞30mg/dl)无确定意义：1.1～1.7mmol/L(20～30mg/dl)结果异常：＜1.1mmol/L(＜20mg/dl)氢水平(呼气)。
空腹：＜5ppm或＜5×10-6乳糖消化后：与空腹时水平相比，升高＜12ppm或＜12×10-6【临床意义】1.乳糖不耐受(1)平直的乳糖耐受曲线(即血糖没有升高)意味着糖分解酶缺乏，也见于肠易激综合征。
此种缺陷在美洲印第安人、非裔美国人、亚洲人、犹太人中较普遍。
(2)后续还需进行单糖耐受试验，如葡萄糖/半乳糖耐受试验。
①患者摄入25g的葡萄糖与半乳糖。
②血糖水平正常升高意味着乳糖缺陷。
(3)继发性乳糖缺乏见于：传染性肠炎；肠道细菌过度生长；炎性肠病，Crohn 病；蓝贾第鞭毛虫侵扰；胰腺囊性纤维化。
2.乳糖缺陷测试中氢呼吸试验异常的原因(1)吸收不良使未被消化的乳糖进入结肠后被细菌发酵，生成氢气(H)。
Lactose ToleranceFrom “Before the Dawn” by Nicholas WadeGeneticists are still trying to define the exact genetic change that causes the lactase gene to stay active after weaning. The DNA sequence of the lactase gene itself is identical in both lactose tolerant and intolerant people. The difference must lie in some nearby region of DNA that controls the activation of the lactase gene, such as the two mutations recently discovered by Leena Peltonen* of the University of Helsinki.What is certain is that the lactose tolerant Europeans have inherited unchanged from a common ancestor a huge block of DNA that includes the lactase gene, its neighboring gene, and much else (located on chromosome 2). The size of the block is a sign of recent evolutionary change. Big blocks of unchanged DNA are very rare because at each generation pairs of chromosomes swap sections of DNA so as to create individuals with novel combinations of genes. As is easy to envisage, the blocks of original DNA that a chromosome may start off with will get smaller and smaller at each generation as the swapping process whittles them down. So a large block of DNA shared by lots of people is a sign of recent selection. Large blocks are created when some must-have mutation occurs that is greatly favored by natural selection. Nature cannot pick out a specific mutation or gene; it can only favor individuals who have inherited the large block of DNA within which the advantageous gene occurs.Besides indicating the presence of a gene under natural selection, a block of DNA can also be used to date the time the gene started to be selected, since the larger it is, the more recent the selection. Joel Hirschhorn** of the Harvard Medical School has found that the block containing the lactase gene in lactose tolerant Europeans extends for about 1 million DNA units. He and colleagues believe that this is a sign of strong positive selection, and that the block started to become widespread sometime between 2,000 and 21, 000 years ago. This date fits with that of the Funnel Beaker culture.Lactose tolerance occurs in a high percentage of many northern Europeans who live in the former region of the Funnel Beaker culture – in 100% of Dutch people, according to one survey, and 99% of Swedes. The condition also occurs in many other populations, though at generally much lower rates. In Africa, tribes who keep cattle, sheep or goats have higher rates of lactose tolerance than nonpastoralists. Lactose tolerance in some African groups includes as much as 25% of the population. It is presumably less common in these African groups than in northern Europeans because pastoralism got started later in Africa and natural selection has had less time to raise the frequency of the gene.Lactose tolerance seems to have a different genetic basis in Africa because the DNA differences found by Peltonen and colleagues to be diagnostic of lactose tolerance in Europeans are largely absent from Africa.The phenomenon of lactose tolerance draws attention to three aspects of human evolution. First, it confirms that evolution didn’t stop 50,000 years ago, when modern humans left Africa, as is often assumed, but has continued to reshape the human genome.Second, it shows the human genome is likely to have responded independently in different populations to the same stimulus, a process known as convergent evolution. Lactose tolerance has arisen independently in northern Europeans and in several African populations. Many other human attributes that have evolved since the African diaspora may also have taken place independently in different populations, such as the probably cognitive advances discussed in Chapter 5.Third, the lactose tolerance phenomenon establishes that genes respond to cultural changes. This is not so surprising because culture is a major part of the human environment, and genomes are mechanisms for responding to the environment. But a feedback of culture on genes is rarely considered by social scientists, many of whom assume that human evolution ended for all practical purposes when cultural development began. The case of lactose tolerance shows that any long lasting human cultural behavior, such as drinking raw milk, can cause genetic changes if there is a way for the genome to respond to it.Looking back on the years between 50,000 and 5,000 years ago, from the time of the ancestral human population to that of the Funnel Beaker people and their contemporaries, it is clear that wrenching changes in the human environment took place during this period, particularly in the social environment. Hunter-gatherers learned to settle down and cooperate in larger groups with people to whom they had no kin relationship. People who had been egalitarian and generalist joined hierarchical societies in which occupations were increasingly specialized. All these changes probably induced different behaviors, some of them maybe mediated through evolutionary changes to the human genome.Human nature, in other words, has probably changed significantly.*/ng/journal/v30/n2/pdf/ng826.pdf**”Genetic Signatures of Strong Recent Positive Selection at the Lactase Gene”, T. Bersaglieri et al., Am J. Hum. Genet. 74:1111-1120, 2004.Funnel Beaker Pottery/epollak/PSY255_pix/lactosedist.JPG。
乳酸降解菌在白酒酿造中的研究进展王新叶，李芳香,张依香，钟艳霞,莫新良，赵 亮*收稿日期：2020-08-17修回日期：2021-03-07基金项目：中国轻工业浓香型白酒固态发酵重点实验室开放基金项目（2018JJ019） ；2019民办高校发展专项基金（myk2019005）；贵州省科学技术基金（黔科合基础［2020］1Y076）；贵州省教育厅青年科技人才成长项目（黔教合KY 字［2018］003,黔教合KY 字［2018］449）;贵州省教育厅项目（黔教合KY 字［2018］451）作者简介:王新叶（1986-）,女,副教授，博士，研究方向为功能微生物。
*通讯作者:赵亮（1983-），男,副教授，博士，研究方向为微生物生态。
（茅台学院 酿酒工程系+贵州仁怀564500）摘要:乳酸降解菌是一类可以利用乳酸作为碳源或者电子受体的微生物，在清香型或浓香型白酒生产过程中加入乳酸降解菌可有效 酒体中乳酸或乳酸乙酯的含量,改善酒体品质。
乳酸 菌一般 酒 中分离得到，因此，将其 到大 或酒'中对其生物的 活动无明显影响。
该文 乳酸 菌的种类、分离筛选策略、乳酸的测 法、乳酸 菌的耐受特 以及乳酸菌在生产上的应五面对乳酸菌的研究进展进行了总，旨在为乳酸降解菌的应用与研究提参考。
关键词:乳酸降解菌;乳酸降解;发酵；白酒中图分类号：TS262.3；TS261.1 文章编号：0254-5071 （2021）06-0007-04doi:10.11882/j.issn.0254-5071.2021.06.002引文格式:王新叶，李芳香,张依香，等•乳酸降解菌在白酒酿造中的研究进展［J ］.中国酿造,2021,40（6）：7-10.Research progress on lactic acid-degrading bacteria in Bai/iu-making processWANG Xinye, LI Fangxiang, ZHANG Yixiang, ZHONG Yanxia, MO Xinliang, ZHAO Liang *(Departement ofBrewin^g Engineering, Moutai Institute, Renhuai 564500, China)Abstract ： Lactic acid degrading bacteria are a kind of microorganism that can utilize lactic acid as carbon source or electron acceptor. Adding lactic acid degrading bacteria in the production of light-flavor or strong-flavor Baijiu (Chinese liquor) can effectively reduce the content of lactic acid or ethyl lactate inliquor and improve the quality of Baijiu . Lactic acid-degrading bacteria were generally isolated from Baijiu -making environment, so adding them to Daquor fermented grains had no obvious effect on the metabolic activities of other microorganisms. In the paper, the research progress of lactic acid-degradingbacteria was summarized from five aspects: the types of lactic acid-degrading bacteria, isolation and screening strategies, determination methods of lacticacid, tolerance characteristics of lactic acid-degrading bacteria and the application of lactic acid-degrading bacteria in production, in order to provide refer ence for the application and research of lactic acid-degrading bacteria.Key words ： lactic acid-degrading bacteria; lactic acid degradation; fermentation; Baijiu乳酸（2-羟基丙酸）（CH s OJ 及其酯类是中国白酒中重要的成分，其在各香型酒中所占的比重差异较大［1］。
intolerance用法Intolerance用法Intolerance是一个英文单词，表示“不宽容”、“不包容”的意思。
在不同的语境中，intolerance可以有不同的用法。
以下是一些常见的用法及详细解释。
1. 宗教不宽容 (Religious intolerance)•宗教不宽容指的是对于不同宗教信仰或者对宗教的敌视或拒绝。
•例如：Religious intolerance has led to numerous conflicts throughout history.•翻译：宗教不宽容导致了许多历史上的冲突。
2. 种族不宽容 (Racial intolerance)•种族不宽容是指对于不同种族的人不友善或具有偏见。
•例如：Racial intolerance remains a significant problem in many societies.•翻译：种族不宽容在许多社会中仍然是一个重大问题。
3. 性取向不宽容 (Intolerance towards sexual orientation)•性取向不宽容指的是对于同性恋、双性恋或其他非传统性取向的不接受或歧视。
•例如：We should promote acceptance and tolerance towards all sexual orientations.•翻译：我们应该推动对所有性取向的接受和宽容。
4. 文化差异不宽容 (Intolerance towards cultural differences)•文化差异不宽容表示对于不同文化的不尊重或不理解。
•例如：Cultural intolerance often arises from a lack of knowledge or exposure to different cultures.•翻译：文化不宽容常常源于对不同文化的缺乏了解或接触。
5. 言论不宽容 (Intolerance towards free speech)•言论不宽容指的是对于不同意见或异议的限制或打压。
半乳糖英文简介Lactose, also known as milk sugar, is a disaccharide composed of glucose and galactose. It is primarily found in milk and dairy products. Lactose is an essential carbohydrate for the growth and development of young mammals, including humans.Lactose is produced in the mammary glands of mammals and serves as the main source of energy in milk. It provides a sweet taste to dairy products and plays a vital role in their nutritional composition. However, not all individuals have the ability to fully digest lactose due to a deficiency in the enzyme lactase, which is responsible for breaking down lactose into its component sugars.Lactose intolerance is a common condition where individuals experience digestive symptoms, such as bloating, gas, and diarrhea, after consuming lactose-containing foods. This intolerance occurs when lactose isnot properly digested and absorbed in the small intestine.In recent years, lactose-free products have become increasingly available to cater to individuals with lactose intolerance. These products undergo a process that breaks down the lactose into its component sugars, glucose and galactose, making them easier to digest.Lactose is also used in various food products as a sweetener and flavor enhancer. It provides a desirable taste profile and is utilized in the production of baked goods, confectionery, and dairy-based desserts.In summary, lactose is a natural sugar found in milk and dairy products. While lactose intolerance is prevalent in certain individuals, lactose-free options are widely available, allowing those with lactose intolerance to still enjoy dairy products without discomfort.。
拉卡托斯(Lactose)是一种有机糖，是乳糖的化学名称，也是人体消化系统中最普遍的糖类物质。
拉卡托斯的研究是有着悠久历史的，它不仅是人体消化系统的重要成分，也是广泛应用于食品工业中的重要原料。
首先，拉卡托斯的研究主要是关于它的结构和性质的。
拉卡托斯是一种双糖，一种由葡萄糖和半乳糖组成的双糖，它具有特殊的结构，这种结构决定了它的溶解性、分子量和分子形状等物理性质，这些性质在它的应用中都有重要意义。
其次，拉卡托斯的研究也与生物学有关。
拉卡托斯在人体的消化系统中是一种重要的营养组分，它可以被人体吸收利用，也可以作为营养素提供给人体。
此外，拉卡托斯也作为微生物的碳源，可以被微生物利用，并可以用来生产酵素和细菌等。
第三，拉卡托斯的研究也与食品工业有关。
拉卡托斯是一种重要的食品添加剂，用于制备乳酸饮料、乳酪、冰淇淋、软糖等食品，因其具有甜味、稳定性和香气等特性，可以改善食品的口感和风味，从而获得更佳的食品品质。
此外，拉卡托斯还可以用于非食品工业，如制药、农药等行业。
最后，拉卡托斯的生产也是一个重要的研究领域。
拉卡托斯可以通过微生物法、化学法等方法从乳制品、植物油脂、植物淀粉等中提取制备而得。
近年来，拉卡托斯的生产技术发展迅速，已成为全球经济发展的重要组成部分。
总之，拉卡托斯的研究是一个复杂而丰富的领域，它既与人体生理有关，也与生物学有关，与食品工业和非食品工业有关，还与生产技术有关。
拉卡托斯的研究具有重要的意义，它不仅可以为食品工业提供有用原料，也可以为人体提供营养，为全球经济发展做出贡献。
《生活大爆炸》经典台词赏析（1）Raj: I don’t like bugs, okay? They freak me out.Sheldon: Interesting. You’re afraid of insects and women. Ladybugs must render you catatonic.Raj：我不喜欢虫子行了吧？快把我吓死了。
Sheldon：有意思。
你害怕虫子，还有女人。
要是见到个花大姐准让你精神失常了。
catatonic直译是“紧张性精神病”，freak sb. out是美俚，是口语中很常见的表达，除了表示把某人吓得半死，也可以表达某事使人情绪波动、失去镇静、行为反常的状态，如：You’d better sit down, this news will freak you out.你最好坐下，这个消息会使你晕倒的。
Going to a funeral naturally makes you freak out about your future.参加葬礼一般都会让你对未来感到崩溃。
（2）Penny:Sheldon,come back.You’re lo sing me.佩妮:谢尔顿，打住，你把我绕晕了。
这是一句非常地道的口语表达。
lose的常用意思为”失去、遗失”，常用形式是lost,也可表示“失落”。
而在“You’re losing me.”里lose的意思则为”使人跟不上、不明白”，相当于confuse。
“跟得上、明白”还可以用with表示，Do you understand me?是比较中式英语的表达。
地道的表达是Are you with me?（3）Sheldon:Worst Renaissance Fair ever.Leonard:Please let it go,Sheldon.You’re nitpicking.Sheldon：史上最烂的文艺复兴集会。
