In recent years, the microbiome has been recognized as a major factor affecting the functioning of host organisms, influencing both health and disease. At the same time, aging research has provided many possible interventional strategies aimed at extending the human lifespan. Several studies have shown a link between the human gut microbiota and aging, as well as how the aging process can affect the structure of the microbiota and its homeostasis with the host immune system. Over the past few decades, the nematode C. elegans has become an important organism for studying aging but more recently, it has been used as a model for microbiome research. C. elegans’ short and easily observable lifespan as well as its defined microbiota can be used as a model to further understand the interactions between microbes and host aging.
In their recent paper, Han et al. used a C. elegans model to identify specific mechanisms by which gut bacteria may influence mitochondrial dynamics and aging. They screened for bacterial mutants that affected aging in their C. elegans model, and identified a specific link between a bacterial polysaccharide and worm mitochondrial dynamics. Their screen was able to identify 29 bacterial mutants out of 3983 that led to an extended lifespan in the worms. Two bacterial mutants which increase production of the polysaccharide colanic acid were chosen for further study because they acted independently of certain pathways associated with longevity and aging. The findings of this paper indicate that the makeup of the microbiota may influence aging in the host organism. This raises the possibility of identifying and using bacterial variants associated with healthy aging with the goal of enhancing human longevity.
On July 28th at 3pm in HSC 3N10A I hope to examine the findings and methods presented in this paper as well as discuss a few key points:
- The advantages and disadvantages of the C. elegans model for microbiome research
- Microbiome modulation of the aging process
- The influence of the microbiome on mitochondrial function
Paper Citation: Han, B., Sivaramakrishnan, P., Lin, C. C. J., Neve, I. A., He, J., Tay, L. W. R., … & Herman, C. (2017). Microbial Genetic Composition Tunes Host Longevity. Cell, 169(7), 1249-1262.