Friday, December 7, 2012

Evolving in a sea of microbes

2012 was the year of the microbiome, the set of bacteria, viruses and fungi living in our noses, mouths and guts. It made national news in June when the Human Microbiome Project first reported on what the bug mix looks like on and in a typical, healthy American.

New understanding of our microbial communities is laying the foundation for advances in the treatment of infectious, autoimmune and inflammatory diseases, including the process by which inflammation contributes to cancer.

For these reasons the UAB Comprehensive Cancer Center chose "cancer and the microbiome" as the theme for its recent research retreat, and The Mix interviewed retreat presenters for a podcast series.

Today's guest is George Weinstock, Ph.D., professor of Genetics at the Washington University School of Medicine.  We talked about his leadership role in genomics revolution, including his contribution to the design of both the Human Genome Project and the Human Microbiome Project.

Show notes for the podcast

1:12 Our world has been dominated by microorganisms for three billion years. All life then involved in this sea of microbes, and humans are no exception.

1:45  Having evolved in a world awash with microbes, the human body is colonized by specific sets of them that provide us with hundreds of times more functions than our own genes can't deliver. Human cells, for instance, have borrowed signalling pathways from microbes that help us digest our food, protect us from being infection, etc.

2:39 Insects have microbiomes too, they they are much simpler than ours. One related theory is that our immune system is more sophisticated because it had to learn to safely handle the many bugs we "invited" to help us digest our food. Taking the idea a step further, some experts think the immune system’s ability to repel unwelcome invaders might represent a lucky, evolutionary after-effect of its more ancient role — managing a stable of helpful bacteria.

3:58 At the heart of Weinstock's decades-long career is DNA sequencing, the technology that enables researchers to determine the order of DNA coding units as a step toward understanding the function of each DNA snippet. The same methods were used to do this for 25 years, but then in 2006 new methods matured that made possible to vastly accelerate the pace of sequencing.  Weinstock's lab can now do in a day what it once took years to do.  For instance, his team can determine the sequence of several human genomes in a day, each requiring the analysis of 3 billion units of code.

6:06 The new high-speed technologies have made possible massive undertakings in genomics, including the 1,000 Genomes ProjectThe ENCODE project and the Human Microbiome Project.

7:06 Weinstock is among the pioneers that helped to launch the Humane Genome Project, which ran from 1998 to 2003 and offered the first estimate of the 20,000 or so genes present in the human blueprint. Before that project, he was among the very first to sequence a genome from any creature, in his case the bacteria responsible for causing syphilis.

9:36 Weinstock also helped to organize the Human Microbiome Project, which this summer published a series of reports in Nature and several Public Library of Science journals that revised the understanding of how microbes drive either health or disease. Researchers from 80 institutions spent five years collecting and sequencing samples from 242 healthy volunteers.

11:07 Bugs don't colonize humans one by one, but instead as part of large, complex communities.  They interact so thoroughly with each other and our cells that they must be analyzed together. Newly available technologies made it possible to analyze the genes of thousands of organisms at once, and the National Institutes of Health decided to invest heavily. The goal is to quickly advance the understanding this huge aspect of human health driven by our microbes. The NIH funded several genome centers to sequence bacterial genomes, with Weinstock's lab among them.

11:34 Beyond just looking at bacteria, the project funded a number of clinical researchers to study how each person's microbiome affects everything from acne to urinary tract infections to the risk for inflammatory disease in premature babies to cancer.

12:28  While the NIH did not think the project would instantly cure diseases (the genomics are too complex), they did hope to understand how you study the microbiome and what resources would be required. 

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