Organic Compounds In Bowel Responsible For Longer Healthier Lives in Variety of Species Interview with:

Daniel Kalman, Ph.D. Department of Pathology and Laboratory Medicine Emory University

Dr. Kalman

Daniel Kalman, Ph.D.
Department of Pathology and Laboratory Medicine
Emory University What is the background for this study? What are the main findings?

  1. We think a lot about living longer, but that means we will also have a longer period of frailty and infirmity, which isn’t optimal. Moreover, with geriatric populations projected to expand by 350 fold over the next 40 years, healthcare costs will be unsustainable.
  2. We were interested in understanding how health span of animals is regulated, and whether the microbiota plays a role. The microbiota, which is composed of bacteria inside and on us, when dysregulated (called dysbiosis) contributes to disease; the question we asked was whether it could also contribute to healthy aging, and how.
  3. We showed that animals of widely divergent phyla and separated by hundreds of millions of years of evolutionary time, all utilize indoles to regulate how well they age; in short indoles  make older animals look younger by various metrics, including motility, and fecundity. What should readers take away from your report?

  1. Basic science studies on simple organisms like worms and flies can be extremely useful in providing information about how humans work.Although simple, these organisms still do a lot of the things we do (e.g. sense bacteria), and evolution has not changed that even over the last 500 million years.
  2. The microbiota is an important regulator of health and disease in organisms. The key question is how the microbiota exerts its effects on animals or on us. Using worms and flies we showed that small molecules called indoles regulate how well we age. That is they can make olds animals move better reproduce longer, and, in effect, look younger. What recommendations do you have for future research as a result of this study?

Response: Given our data with worms and flies and mice, and observations of others  that indole levels are dysregulated in people with chronic inflammatory diseases (e.g. IBD), it is not unreasonable to hypothesize that indoles likewise control health span in us. We are testing that idea in various ways; it will take time and further experimental work to do this, and to develop means to introduce or restore indoles in people to levels that are both efficacious and safe. While such therapeutics will never allow us to remain immortal or forever young, they might be able to limit infirmity, which might be useful, particularly in geriatric people.

No disclosures Thank you for your contribution to the community.


Robert Sonowal, Alyson Swimm, Anusmita Sahoo, Liping Luo, Yohei Matsunaga, Ziqi Wu, Jui A. Bhingarde, Elizabeth A. Ejzak, Ayush Ranawade, Hiroshi Qadota, Domonica N. Powell, Christopher T. Capaldo, Jonathan M. Flacker, Rhienallt M. Jones, Guy M. Benian, and Daniel Kalman. Indoles from commensal bacteria extend healthspan. PNAS, August 21, 2017 DOI: 10.1073/pnas.1706464114

Note: Content is Not intended as medical advice. Please consult your health care provider regarding your specific medical condition and questions.

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Last Updated on August 22, 2017 by Marie Benz MD FAAD