生物谷報(bào)道：相信很多人都熱愛(ài)干凈的生活環(huán)境，甚至恨不得自身體內(nèi)也一個(gè)細(xì)菌都不存在,。但是請(qǐng)注意，過(guò)分的干凈并不會(huì)給你帶來(lái)任何的好處。美國(guó)科學(xué)家近日通過(guò)對(duì)果蠅的研究表明,，無(wú)菌果蠅并不會(huì)比體內(nèi)充滿細(xì)菌的果蠅生活得更長(zhǎng)久。這無(wú)疑將對(duì)人類(lèi)的老化研究產(chǎn)生重要的影響,。相關(guān)論文發(fā)表在8月8日的《細(xì)胞－代謝》雜志上,。
該項(xiàng)研究由美國(guó)南加州大學(xué)的分子與計(jì)算生物學(xué)副教授John Tower領(lǐng)導(dǎo)完成。他和同事比較了無(wú)菌果蠅（該種果蠅產(chǎn)自用抗生素清洗過(guò)的果蠅卵,，并一直在無(wú)菌環(huán)境中用消過(guò)毒的食物喂養(yǎng)）和普通果蠅后發(fā)現(xiàn),，這兩種果蠅具有大致相同的壽命。這表明細(xì)菌并不會(huì)加速果蠅的死亡,。
雖然此次實(shí)驗(yàn)無(wú)法在人類(lèi)身上應(yīng)用（人類(lèi)身體需要一定量的細(xì)菌以完成各種生理功能）,，但由于人類(lèi)與果蠅具有類(lèi)似的對(duì)細(xì)菌的先天免疫反應(yīng)，所以此次的發(fā)現(xiàn)將有助于科學(xué)家對(duì)人類(lèi)的老化展開(kāi)更深入的研究,。（科學(xué)網(wǎng) 梅進(jìn)/編譯）
原始出處:
Cell Metabolism, Vol 6, 144-152, 08 August 2007
Short Article
Increased Internal and External Bacterial Load during Drosophila Aging without Life-Span Trade-Off
Chunli Ren,1 Paul Webster,2 Steven E. Finkel,1 and John Tower1,
1 Molecular and Computational Biology Program, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089-2910, USA
2 Ahmanson Advanced Electron Microscopy and Imaging Center, House Ear Institute, Los Angeles, CA 90057, USA
Corresponding author
John Tower
[email protected]
The role of microbial load during aging of the adult fruit fly Drosophila melanogaster is incompletely understood. Here we show dramatic increases in aerobic and anaerobic bacterial load during aging, both inside the body and on the surface. Scanning electron microscopy and cell staining analyses of the surface of aged flies detected structures resembling abundant small bacteria and bacterial biofilms. Bacteria cultured from laboratory flies included aerobic species Acetobacter aceti, Acetobacter tropicalis, and Acetobacter pasteurianus and anaerobic species Lactobacillus plantarum and Lactobacillus sp. MR-2; Lactobacillus homohiochii, Lactobacillus fructivorans, and Lactobacillus brevis were identified by DNA sequencing. Reducing bacterial load and antimicrobial peptide gene expression by axenic culture or antibiotics had no effect on life span. We conclude that Drosophila can tolerate a significant bacterial load and mount a large innate immune response without a detectable trade-off with life span; furthermore, microbes do not seem to limit life span under optimized laboratory conditions.
