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House dust exposure mediates gut microbiome
Lactobacillus enrichment and airway immune defense
against allergens and virus infection
Kei E. Fujimuraa,Tine Demoorb, Marcus Raucha, Ali A. Faruqia, Sihyug
Jangb, Christine C. Johnsonc, Homer A. Bousheyd, Edward Zorattie,
Dennis Ownbyf, Nicholas W. Lukacsb and Susan V. Lyncha
報告學生:林政男
日期:2015.12.13
Kei E. Fujimura et al. PNAS 2014;111:805-810
INTRODUCTION
• The key role microbial communities play in a variety
of critical mammalian processes including ancillary
mucosal barrier function and metabolism
• A significant increase in the number of Escherichia
coli or Clostridium difficile in fecal samples from 3wk-old infants --a greater risk of developing a
spectrum of childhood allergic diseases commonly
characterized by overactive Th2 adaptive immune
response.
INTRODUCTION
1.Antibiotic administration and caesarian
section delivery-- increased risk for
childhood asthma.
2.Exposure to livestock or pets, particularly
dogs during this early-life period,
significantly decreases the risk for
disease development .
3.Local environmental microbial exposures
influence microbiome membership and
the immune response of the human host
INTRODUCTION
1. GI microbiome composition clearly
impacts immune function, and early GI
colonization patterns are linked to
allergic disease development
2.It is necessary to understand whether and
how distinct environmental microbial
exposures associated with allergyprotective factors influence GI
microbiome composition and airway
disease outcomes.
RESULTS
Exposure of animals to dust from homes with dogs
attenuates the development of allergen-induced airways
disease and serum IgE.
1. indoor/outdoor
dog(D)
2. No pet(NP)
3. cockroach
allergen (CRA)challenged mice
Exposure to D-associated house dust alters host
responses to two distinct antigen systems via modulation
of both T-cell numbers and activity
Kei E. Fujimura et al. PNAS 2014;111:805-810
Exposure to house dust alters cecal microbiome
composition.
This species resides intaxon 7028 (represented by
Lactobacillus gasseri)-- a high degree of concordance
between molecular and culture-based assessments of the
cecal microbiome of these animals.
Kei E. Fujimura et al. PNAS 2014;111:805-810
Supplementation of mice with L. johnsonii attenuates the
development of allergic airways disease.
L. johnsonii plays a pivotal role in airway protection
Kei E. Fujimura et al. PNAS 2014;111:805-810
Viable L. johnsonii is necessary to attenuate RSV-induced
airway responses.
L. johnsonii supplementation significantly reduced the RSV
induced pulmonary responses and that viable organisms are
necessary to transduce the altered responses.
Kei E. Fujimura et al. PNAS 2014;111:805-810
L. johnsonii-supplemented animals that exhibit airway
protection exhibit altered cecal microbiome composition.
Those taxa significantly enriched in L. johnsoniisupplemented mice included members of the Rikenellaceae II
(primarily organisms of GI origin), whereas unprotected
animals were characterized by enrichment of
Lachnospiraceae and Ruminococceaceae, including
Clostridium and Bacteroides species
Kei E. Fujimura et al. PNAS 2014;111:805-810
回顧
1. 作者利用小鼠模式，發現暴露在養狗環境收集來的灰塵能夠
保護動物抵抗卵清蛋白或蟑螂引起的呼吸道過敏原。受到保
護的動物其呼吸道中的T細胞總數明顯降低，且Th2相關的
呼吸道反應及黏液分泌也因此調降。
2. 伴隨暴露在養狗環境收集來的灰塵中，受到保護的動物盲腸
中微生物大量重組，明顯含有豐富的其他菌種: L.johnsonii。
3. 餵食老鼠L.johnsonii可保護他們抵抗呼吸道過敏原侵害或呼
吸道融合病毒的感染。L.johnsonii 調控的保護機制是減少活
化的CD11c(+)/CD11b(+) 和 CD11c(+)/CD8(+) 細胞的總數和
比例，以及降低呼吸道 Th2 細胞激素的表達。
Conclusion
作者的研究結果顯示，暴露於養狗環境收集來的灰塵中，會
產生保護效果，抵抗免呼吸道過敏原侵害以及改變腸道菌相
的組成。此外，這項研究發現L.johnsonii是重要的菌屬，能
夠影響控制粘膜表面的後天免疫保護作用，保護動物抵抗各
種不同的呼吸道刺激。
Thanks for your attention ！
• 梭菌屬（Clostridium），菌體呈梭狀，又稱梭狀芽孢桿菌
屬或厭氧芽孢桿菌屬，芽孢常比菌體大，是一類能產生內
生孢子的厭氣性革蘭氏陽性菌。
• 梭菌屬廣泛分布於自然界，以土壤中最多，芽孢圓形或橢
圓形。除了產氣莢膜梭菌無鞭毛外，大多有鞭毛。大部份
的梭菌屬可以水解糖、蛋白質，又可產生外毒素。
EX:梭狀桿菌 (Clostridium difficile) 為一種革蘭氏陽性、產孢子
之厭氧桿菌。
https://zh.wikipedia.org
擬桿菌門(Bacteroidetes)包括三大類細菌，即擬桿
菌綱、黃桿菌綱、鞘脂桿菌綱。它們的相似性體現
在核糖體16S RNA。
很多擬桿菌綱的細菌種類生活在人或者動物的腸道
中，有些時候成爲病原菌。在糞便中，以細胞數目
計，擬桿菌屬(Bacteroides)是主要微生物種類。
https://zh.wikipedia.org