Aging in Caenorhabditis elegans- nature versus

nuture (or a diet of E. coli)? The first genes extending lifespan were identified in the nematode Caenorhabditis elegans [1], and several of the metabolic pathways they are involved in are conserved in other species, including flies, mice and humans. Some of the pioneering studies on aging in C. elegans made use of RNA interference (RNAi) to manipulate gene expression, a strategy that is easily applied in C. elegans by feeding the worms on Escherichia coli strains expressing the relevant RNA sequence. However, it is becoming increasingly clear that the E. coli diet itself can have profound affects on C. elegans lifespan, and the degree of bacterial colonization within the worm gut has been shown to correlate inversely with worm lifespan [2]. In a recent paper in BMC Biology, Vir