研究發現養狗可防幼兒哮喘大綱

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.

科學家們研究了養寵物為何似乎能保護孩子不會患上哮喘與過敏，他們說，答案可能在於腸道內生活的菌群。

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.

週一公佈的新研究發現，將老鼠暴露於准許狗外出的家庭產生的灰塵中，極大地改變了老鼠腸道菌群的成分。

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.

隨後這些老鼠被注射了一些有名的過敏觸發物，相比那些暴露於無狗家庭灰塵或是未暴露於灰塵中的老鼠，這些老鼠的過敏反應大大減小。

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.

加州大學舊金山分校(University of California, San Francisco)腸胃病學副教授、上述研究的資深作者林奇(Susan Lynch)說，在家中養狗可能對嬰兒胃腸道起到接種作用，導致更為成熟的免疫反應，對許多過敏原較不敏感。上述研究發表在《美國國家科學院院刊》(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.

林奇說，我們在一生中最初的幾年就在腸道中建立了這種極為多樣化的生物群落。胃腸道微生物群正成為越來越多的研究機構的研究物件，這些研究顯示出，細菌在新陳代謝、免疫和多種生物過程中都扮演著關鍵角色。

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.

雖然上述研究考察的是老鼠的情況，但林奇說，相關結果與此前基於人類觀察的研究一致，並有可能適用於人類。

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.'

新的研究識別出了一種名為約氏乳酸桿菌(Lactobacillus johnsonii)的細菌，其與防止過敏反應存在很強的關聯。林奇說，從一組老鼠的腸道中分離出這種細菌並植入另外的老鼠腸道後，被植入細菌的老鼠就獲得了過敏保護。這些動物身上的免疫反應極大地降低了，它們看起來更為健康。

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

但它們受到保護的程度不如有著更多樣化菌群的老鼠，這表明菌群中還有其他類似生物影響著免疫反應。

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.

林奇與密歇根大學(University of Michigan)、底特律亨利・福特衛生系統(Henry Ford Health System)以及奧古斯塔Georgia Regents University的研究人員正將這項研究轉向人體。林奇說，研究的目標是開發出基於益生菌或微生物的療法，可能用於防止或治療哮喘和過敏。

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

這項研究由美國國家健康研究院(National Institutes of Health)下屬的美國國家過敏症和傳染病研究所(National Institute of Allergy and Infectious Diseases)資助。