嬰兒早期腸道中如果繁殖有大量的大腸桿菌,，則嬰兒機(jī)體的血液中將會(huì)有較多數(shù)量的記憶B細(xì)胞，近日,，來(lái)自瑞典歌德堡大學(xué)的研究者這樣表示,。相關(guān)研究成果刊登在了國(guó)際雜志The Journal of Immunology上。
我們腸道中的細(xì)菌遠(yuǎn)遠(yuǎn)超過(guò)我們機(jī)體中的細(xì)胞數(shù)量,，而且這些細(xì)菌對(duì)于機(jī)體的健康至關(guān)重要,，因?yàn)榧?xì)菌可以刺激人類(lèi)機(jī)體的免疫系統(tǒng)成熟。一般情況下,，正常的腸道細(xì)菌菌群是在我們?nèi)祟?lèi)生命初期開(kāi)始建立的,，但是近年來(lái)人類(lèi)增加的衛(wèi)生生活方式改變了細(xì)菌菌群。
目前來(lái)講,，大腸桿菌在瑞典的兒童的腸道中寄居時(shí)間越來(lái)越晚,，而且在腸道中開(kāi)始存在少量各種各樣的不同的細(xì)菌，于此同時(shí),，因?yàn)槊庖哒{(diào)節(jié)缺失所引起的疾病不斷增加,，使得變態(tài)反應(yīng)成為西方國(guó)家一個(gè)主要的公眾健康問(wèn)題。
B細(xì)胞在變態(tài)反應(yīng)發(fā)展的過(guò)程中扮演者重要角色
B細(xì)胞是一種白細(xì)胞,，可以通過(guò)產(chǎn)生抗體來(lái)保護(hù)機(jī)體免受感染以及在變態(tài)反應(yīng)的發(fā)展過(guò)程中起到了關(guān)鍵的作用,。研究者們通過(guò)對(duì)B細(xì)胞進(jìn)行相關(guān)研究，以及Vastra Gotaland地區(qū)65個(gè)健康新生兒的相關(guān)研究,，表明在出生一周的嬰兒腸道內(nèi)如果有大腸桿菌寄居的話,，在嬰兒成長(zhǎng)至4個(gè)月和18個(gè)月的時(shí)候，其體內(nèi)的記憶B細(xì)胞數(shù)量會(huì)大量增加,。這樣的結(jié)果對(duì)于我們理解腸道細(xì)菌菌群和免疫系統(tǒng)發(fā)展之間的關(guān)系至關(guān)重要,，而且提醒我們過(guò)度衛(wèi)生生活方式多帶來(lái)的健康風(fēng)險(xiǎn)。
研究者表示,，人類(lèi)周?chē)牡拇蟛糠旨?xì)菌都是無(wú)害的,，我們應(yīng)該視它們?yōu)殄憻捨覀儥C(jī)體免疫力的一種鍛煉方式，一遍我們的免疫系統(tǒng)可以成熟地更加完全,，健康的新生兒并不需要過(guò)度保護(hù)而使其不與細(xì)菌接觸,。（生物谷：T.Shen<微博>編譯）
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doi:10.4049/jimmunol.1103223
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Infant B Cell Memory Differentiation and Early Gut Bacterial Colonization
Anna-Carin Lundell*, Viktor Björnsson*, Annika Ljung†, Margareta Ceder‡, Susanne Johansen§, Gunhild Lindhagen¶, Carl-Johan Törnhage‖, Ingegerd Adlerberth†, Agnes E. Wold† and Anna Rudin*
Germ-free animal models have demonstrated that commensal bacterial colonization of the intestine induces B cell differentiation and activation. Whether colonization with particular bacterial species or groups is associated with B cell development during early childhood is not known. In a prospective newborn/infant cohort including 65 Swedish children, we examined the numbers and proportions of CD20+, CD5+, and CD27+ B cells in blood samples obtained at several time points during the first 3 y of life using flow cytometry. Fecal samples were collected and cultured quantitatively for major facultative and anaerobic bacteria at 1, 2, 4, and 8 wk of life. We found that the numbers of CD20+ B cells and CD5+CD20+ B cells reached their highest levels at 4 mo, whereas CD20+ B cells expressing the memory marker CD27 were most numerous at 18 and 36 mo of age. Using multivariate analysis, we show that early colonization with Escherichia coli and bifidobacteria were associated with higher numbers of CD20+ B cells that expressed the memory marker CD27 at 4 and 18 mo of age. In contrast, we were unable to demonstrate any relation between bacterial colonization pattern and numbers of CD20+ or CD5+CD20+ B cells. These results suggest that the intestinal bacterial colonization pattern may affect the B cell maturation also in humans, and that an early gut microbiota including E. coli and bifidobacteria might promote this maturation.
