生物谷报道:相信很多人都热爱干净的生活环境,甚至恨不得自身体内也一个细菌都不存在。但是请注意,过分的干净并不会给你带来任何的好处。美国科学家近日通过对果蝇的研究表明,无菌果蝇并不会比体内充满细菌的果蝇生活得更长久。这无疑将对人类的老化研究产生重要的影响。相关论文发表在8月8日的《细胞-代谢》杂志上。
该项研究由美国南加州大学的分子与计算生物学副教授John Tower领导完成。他和同事比较了无菌果蝇(该种果蝇产自用抗生素清洗过的果蝇卵,并一直在无菌环境中用消过毒的食物喂养)和普通果蝇后发现,这两种果蝇具有大致相同的寿命。这表明细菌并不会加速果蝇的死亡。
虽然此次实验无法在人类身上应用(人类身体需要一定量的细菌以完成各种生理功能),但由于人类与果蝇具有类似的对细菌的先天免疫反应,所以此次的发现将有助于科学家对人类的老化展开更深入的研究。(科学网 梅进/编译)
原始出处:
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
jtower@usc.edu
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.