Interplay between mitochondria and diet mediates pathogen and stress resistance in Caenorhabditis elegans.

To understand the impact of a diet on host health, we performed a number of assays with C. elegans reared on OP50 or HT115 E. coli. We observed that HT115 provided a substantial increase in resistance to Liquid Killing and abiotic stresses (e.g., heat shock, oxidative stress). This phenomenon was independent of the worms innate immune system. In the absence of any other obvious candidates, we turned to microarray transcriptional profiling to gain an unbiased picture of the differences that result from feeding C. elegans with HT115 instead of OP50. To our surprise, there was a relatively small number of genes differentially expressed between worms fed OP50 and HT115. Amongst them were several mitochondrially-associated genes, suggesting that the relevant difference may involve this organelle. Using a variety of approaches, we determined that worms fed HT115 exhibit increased mitochondrial health than their OP50 counterparts. Furthermore, supplementation of growing OP50 with cobalamin recapitulated virtually all of the HT115 phenotypes.为探究饮食对宿主健康的影响，我们以喂食OP50或HT115大肠杆菌的秀丽隐杆线虫（C. elegans）为实验材料，开展了一系列实验检测。我们观察到，相较于喂食OP50的线虫，喂食HT115的线虫对液体杀伤及非生物胁迫（如热激、氧化应激）的抗性显著增强。该现象不依赖于线虫的先天免疫系统。 在未发现其他明确候选机制的前提下，我们采用微阵列转录组分析，以无偏的方式解析以HT115而非OP50喂食的线虫之间的基因表达差异。令人意外的是，两组间差异表达的基因数量相对较少，其中包含多个线粒体相关基因，提示相关差异可能与线粒体这一细胞器有关。 通过多种实验手段，我们证实喂食HT115的线虫其线粒体健康水平显著高于喂食OP50的对应组别。此外，向处于增殖培养阶段的OP50菌株添加钴胺素（维生素B12），几乎可重现HT115诱导的全部表型。