Bacteria-Host Interaction and Aging Mechanisms
We use the round worm, Caenorhabditis elegans as a model system to investigate how commensal bacteria affect the physiology and aging of their hosts.
Bacteria are not merely food for C. elegans. They colonize adult worms and can dramatically influence the animal’s behavior and life span. Similarly, billions of bacteria colonize the mammalian digestive tract, including that of the human. However, their effects on human wellbeing and lifespan remain largely unknown.
In the laboratory, C. elegans is fed almost exclusively on E. coli. However, in their natural habitat these nematodes consume soil bacteria, such as Bacilli. Remarkably, worms fed B. subtilis live twice as long as those fed E. coli. We identified several key metabolites produced by B. subtilis that extend the life span of the worm and render it more resistant to environmental stressors such as heat and oxidants.
We are designing probiotic strains of bacteria that significantly extend the nematode life span. We also investigate the mechanisms by which bacteria-derived small molecules increase nematode longevity. Separately, we study how different forms of commensal bacterial communities (e.g. biofilms) influence the nematode life span and resistance to stress and infection.