飞机维护手册:少少不干不净或许是件好事儿

一些专家说，人体为保护自身健康，必须学会承受部分细菌存在。

九月九日《健康日新闻》记者丹尼斯·汤普森报导，根据美国疾病控制和预防中心的资料，良好的卫生习惯，使人们免除了无数细菌和病毒的感染，拯救了千百万人的生命。

但严格遵守良好的卫生习惯，越来越多的被受关注，虽然保持卫生是保护健康的宝贵手段，但却给人类造成其他形式的疾病。

Proponents of the "hygiene hypothesis" believe that reduced exposure to bacteria, viruses and parasites have impaired the immune system's ability to properly respond to environmental challenges.

Researchers have identified the hygiene hypothesis as a possible cause or exacerbating factor in a number of illnesses and medical problems, said Dr. Graham A.W. Rook, a professor in the department of infection at the Centre for Clinical Microbiology at the University College London. These include:

“卫生假说”的支持者们认为，减少对细菌、病毒和寄生虫的暴露，会损伤免疫系统妥善应对环境挑战的能力。

英国伦敦大学临床学院微生物学中心感染科教授Rook博士说，在某些疾病和医疗问题中，研究人员已经确定“卫生假说”可能导致或加剧疾病的因素。包括下列病患：

·

Severe allergic reactions. 

·

Gastrointestinal disorders, such as inflammatory bowel disease and Crohn's disease. 

·

Autoimmune disorders, such as type 1 diabetes and multiple sclerosis.

"The evidence for all this is very, very powerful," Rook said. "It's very easy to show if you live on a farm or keep a dog, you're less likely to have these disorders. If you are the youngest child in a big family, you're less likely to have these disorders."

•严重的过敏反应。

•胃肠功能紊乱，如炎症性肠道疾病和克罗恩病。

•自身免疫性疾病，如1型糖尿病和多发性硬化症。

“所有这些疾病的证据是非常，非常有力的，”Rook说，“这很容易证明，如果你住在农场或养狗，你就不太可能有这些疾病的，如果你是一个大家庭中最小的孩子，你也不太可能有这些疾病。”

The hygiene hypothesis has its roots in the theory of evolution, he said.

"The bottom line is organisms that were present in mud, untreated water and feces were with us right from the start of humanity," Rook explained. Proponents of the hygiene hypothesis believe that the human body adapted to these organisms and began using them as a means of training the immune system.

"What has happened over the course of evolution is, because these bugs had to be tolerated, they came to activate the tolerance of the immune system," Rook said. "They are the police force that keeps the immune system from becoming trigger-happy. Basically, the immune system is now attacking things it shouldn't be attacking."

他说，卫生假说是有进化理论根据的。

Rook博士解释说，“从人类诞生开始，存在于泥土、未经处理的水和粪便中的微生物就伴随我们一起生存。”卫生假说的支持者认为，人体适应这些微生物，并开始利用他们作为训练免疫系统的一种方法。

“在进化过程中，因为人体必须承受这些微生物，以此激活人体免疫系统的承受能力，”Rook说。 “他们是警察部队，抑制免疫系统的快乐扳击。基本上，免疫系统现在反常攻击的对象，它不应该攻击。”

Dr. Mitchell H. Grayson, an associate professor of pediatrics at the Medical College of Wisconsin in Milwaukee, said that the hygiene hypothesis is most strongly linked to an increase in allergic diseases and asthma.

"It's thought to have something to do with the way your immune system develops and is programmed," Grayson said. Bacteria in the environment teach an immune response to allergens that is more moderate and less severe. "In the absence of these bacteria, the immune system is thought to become more prone to allergic disease," he said.

威斯康新医学院儿科副教授格雷森博士说，“卫生假说”与过敏性疾病和哮喘的相关性越来越强。

“现在认为卫生假说与我们的免疫系统的发生和完善有关，”格雷森说，环境中的细菌诱导免疫系统对过敏原产生较为温和的和不太严重的反应。 “如果没有这些细菌存在，免疫系统变得更容易出现过敏性疾病，”他说。

Rook said that other researchers have used the hygiene hypothesis to show that parasitic infections can aid in the treatment of such conditions as multiple sclerosis and Crohn's disease.

Rook说，其他研究人员利用卫生假说治疗疾病的实践结果表明，寄生虫感染能帮助治疗多发性硬化病和克罗恩病等免疫性疾病。

Argentinean researchers, for instance, have shown that the presence of intestinal parasites can moderate the progression of multiple sclerosis. Follow-up studies indicated that, when people were treated for their parasitic infection, they had a relapse of MS.

A research team at the University of Iowa found similar results related to Crohn's disease, showing that intestinal parasites helped regulate the autoimmune reaction that causes the intestinal disorder.

例如，阿根廷研究人员证实，肠道寄生虫可以减缓多发性硬化症的进展。后续研究表明，当寄生虫感染被清除后，多发性硬化症即复发。

美国爱荷华州大学的一个研究小组研究克罗恩病时也获得类似的结论，即肠道寄生虫有助于调节导致肠道疾病的自体免疫反应。

On the flip side, such revelations carry risks. Doctors are concerned that some might use the hygiene hypothesis as an excuse to abandon good hygiene, causing a surge in diseases such as dysentery and cholera.

"Public health and sanitation has been the single greatest improvement in our life expectancy," Grayson said. "I would not recommend living less cleanly."

On the other hand, tolerance of a little dirt here and there won't hurt.

但另一面，卫生假说的启示也存在风险。医生们担心某些人以此为借口，放弃良好的卫生习惯，导致痢疾和霍乱等疾病激增。

“公共卫生与健康一直是增加我们预期寿命最大的促进因素，”格雷森说。 “我不会推荐生活可以不那么干净。”

另一方面，经常在某些地方有点儿不干净也不会有什么伤害。

"If your kids come back from the garden with a little mud on their hands, it's not a bad thing," Rook said. "They don't necessarily have to wash their hands before picking up a sandwich."

“如果你的孩子从花园回来时，手上有点儿泥土，那不是一件坏事，”Rook说。 “他们并非必须洗手后才可拿三明治。”

In general, though, it's wise to maintain good overall hygiene, he said, and wait for the scientists to figure all this out. Larger studies are underway to determine the exact mechanism by which bacteria and parasites are causing the immune system to moderate its response, Rook said.

"We need to figure out how to replace what is good from the microbiological environment while maintaining the advances of good hygiene so we can get the best of both worlds," Rook said.

说，还要等待科学家研究出更明确的结论。正在进行更大规模的研究，以确定细菌和寄生虫诱发免疫系统调适免疫反应的确切机制。

Rook说：“我们需要弄清楚如何保持良好的卫生优势，又同时承受一个什么样的微生物环境，使我们可以得到两全其美。”