研究发现养狗可防幼儿哮喘

Scientists studying why pets appear to protect kids against asthma and allergies say the answer might lie in the world of bacteria that live in the gut.

科学家们研究了养宠物为何似乎能保护孩子不会患上哮喘与过敏，他们说，答案可能在于肠道内生活的菌群。

A new study published Monday found that exposing mice to dust from households where dogs were allowed outdoors significantly changed the composition of gut microbes in the mice.

周一公布的新研究发现，将老鼠暴露于准许狗外出的家庭产生的灰尘中，极大地改变了老鼠肠道菌群的成分。

When the mice were then challenged with some well-known allergy triggers, they had significantly reduced allergic responses compared with mice that had been exposed to dust from homes without dogs or that weren't exposed to any dust.

随后这些老鼠被注射了一些有名的过敏触发物，相比那些暴露于无狗家庭灰尘或是未暴露于灰尘中的老鼠，这些老鼠的过敏反应大大减小。

Having dogs in the house 'might inoculate the GI tract' of babies and lead to a more mature immune response that is less sensitive to many allergens, said Susan Lynch, an associate professor in the division of gastroenterology at University of California, San Francisco and senior author of the study, published in the Proceedings of the National Academy of Sciences.

加州大学旧金山分校(University of California, San Francisco)肠胃病学副教授、上述研究的资深作者林奇(Susan Lynch)说，在家中养狗可能对婴儿胃肠道起到接种作用，导致更为成熟的免疫反应，对许多过敏原较不敏感。上述研究发表在《美国国家科学院院刊》(Proceedings of the National Academy of Sciences)。

'We develop this great diversity of organisms [in the gut] over the first couple of years of life,' Dr. Lynch said. The gastrointestinal microbiome is the subject of a growing body of research showing the bacteria play key roles in metabolism, immunity and a variety of other biological processes.

林奇说，我们在一生中最初的几年就在肠道中建立了这种极为多样化的生物群落。胃肠道微生物群正成为越来越多的研究机构的研究对象，这些研究显示出，细菌在新陈代谢、免疫和多种生物过程中都扮演着关键角色。

While the study looked at mice, Dr. Lynch said the findings are consistent with previous research based on human observations and are likely to apply to people.

虽然上述研究考察的是老鼠的情况，但林奇说，相关结果与此前基于人类观察的研究一致，并有可能适用于人类。

The new study identified one specific species of bacteria, Lactobacillus johnsonii, that was strongly linked to protection against allergic responses. When isolated from the gut of one group of mice and put into the intestinal tract of other mice, 'those mice were protected,' Dr. Lynch said. 'The immune response was significantly reduced in those animals and they looked healthier.'

新的研究识别出了一种名为约氏乳酸杆菌(Lactobacillus johnsonii)的细菌，其与防止过敏反应存在很强的关联。林奇说，从一组老鼠的肠道中分离出这种细菌并植入另外的老鼠肠道后，被植入细菌的老鼠就获得了过敏保护。这些动物身上的免疫反应极大地降低了，它们看起来更为健康。

But they weren't as well-protected as mice with a more-diversified microbiome, suggesting other such organisms in the microbiome affect immune response.

但它们受到保护的程度不如有着更多样化菌群的老鼠，这表明菌群中还有其他类似生物影响着免疫反应。

Dr. Lynch and her colleagues, including researchers at the University of Michigan; the Henry Ford Health System, Detroit; and the Georgia Regents University, Augusta, are shifting the research to people. The aim is to develop probiotics or 'microbial based therapies' that might be used to prevent or treat asthma and allergies, Dr. Lynch said.

林奇与密歇根大学(University of Michigan)、底特律亨利・福特卫生系统(Henry Ford Health System)以及奥古斯塔Georgia Regents University的研究人员正将这项研究转向人体。林奇说，研究的目标是开发出基于益生菌或微生物的疗法，可能用于防止或治疗哮喘和过敏。

The study was funded by the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health.

这项研究由美国国家健康研究院(National Institutes of Health)下属的美国国家过敏症和传染病研究所(National Institute of Allergy and Infectious Diseases)资助。