Accumulating evidence suggests that microbiota plays an important role in modulating lifespan. This makes possible to use symbiotic bacteria as “living drugs”, which live in the host organism and promote its longevity. We propose to create bacteria, which dramatically extend lifespan of its host. Such bacteria have to produce not one, but a set of longevity-promoting substances with optimal concentrations and dynamics of secretion. To obtain such bacteria we propose to use directed evolution, a process that mimics Darwinian selection on a laboratory scale. This approach has never been applied to drug development before. Directed evolution enables simultaneous modulation of a number of bacterial metabolic pathways andsubsequent selection of the most effective longevity-promoting variants. Experiments will be conducted on a model system consisting of C.elegans and its intestinal symbiont E.coli. Due to highly conserved aging pathways, obtained bacteria may be further used to develop longevity-promoting human drug.
Bacteria E.coli serve as the food source for C.elegans, but at particular stages of the nematode life course they can also exist as intestinal symbionts. Moreover, it was shown that E.coli influence physiology and lifespan of C.elegans. It was revealed that several mutations in E.coli genome increase or vice versa reduce the nematode lifespan.