In the past 100 years we’ve learned that each one of us has unique fingerprints, and unique DNA sequences. Now through the Human Microbiome Project, we’re learning that every one of us has a unique and identifiable bacterial community not only inside of us, but also growing on our skin as well. Christian Lauber, a postdoc in the Fierer lab at the University of Colorado talked with us about their recent work to elucidate skin microbiomes.
Q: Recently your group published a paper in PNAS where you demonstrated it is possible to link individuals to objects that they have touched by comparing the bacterial community on hands and computer keyboards. What led you to conduct this study?
A: In earlier work, we looked at the diversity of bacteria living on different people’s hands, how it changed over short periods of time and what happened to bacterial communities after hand washing and treatment with Ethanol. Surprisingly we discovered that every person we tested had a unique bacterial community that would re-establish itself within 2 hours of hand washing. Even when hands were washed with Ethanol, those bacteria would regrow relatively quickly without much change. Given the resilience of these bacteria we surmised that those bacteria would likely transfer to objects that are frequently touched by an individual.
Q: How foolproof is the idea that bacterial communities are completely unique to individuals? Are there commonalities between members of families living in the same house or between parents and children?
A: Further work needs to be done to determine how relationships and proximity impacts these bacterial communities. However, all of our current work says that most people’s bacterial communities are fairly unique. Currently we’re evaluating the microbiomes of relatively healthy volunteers. But eventually we hope to link changes and differences in human bacterial communities to disease states.
Q: Can personal bacterial communities change over time?
A: Currently we’re evaluating the microbiomes of relatively healthy volunteers at single timepoints. Our future projects will include a wider demographic of volunteers from more age groups and health backgrounds. Eventually we hope to link changes and differences in human bacterial communities to disease states, such as colon cancer, Irritable Bowel Syndrome and Crohn’s disease.
Q: How have MO BIO’s products assisted you in doing this work?
A: MO BIO’s PowerSoil kit has an extremely high success rate for PCR. 95% of DNA samples extracted with this kit just work in our PCR reactions. Most other kits have a 50% success rate. We use this kit for all of the samples that we process. Also, because bacterial DNA is so prevalent, we find that the Certified DNA-Free PCR water is key to preventing non-specific amplification in our reactions.
In this video, Dr. Fierer and Dr. Lauber talk about their work on microbial communities on skin:
For more information and a complete publication list, please visit the Fierer’s lab website: http://www.colorado.edu/eeb/EEBprojects/FiererLab/index.html
Related papers include:
Dominguez-Bello, M.G., E.K. Costello, M. Contreras, M. Magris, G. Hidalgo, N. Fierer, R. Knight. In Press. Delivery mode shapes the acquisition and structure of the founder microbiota across multiple body habitats in newborns. Proc. Natl. Acad. Sci. USA. Jun 2010; 10.1073/pnas.1002601107.
Fierer, N., C.L. Lauber, N. Zhou, D. McDonald, E.K. Costello, R. Knight. 2010. Forensic identification using skin bacterial communities. Proc. Natl. Acad. Sci. USA. 107: 6477-6481.
Costello, E.K., C.L. Lauber, M. Hamady, N. Fierer, J.I. Gordon, R. Knight. 2009. Bacterial variation in human body habitats across space and time. Science. 326: 1694-1697
Fierer, N. M. Hamady, C.L. Lauber, R. Knight. 2008. The influence of sex, handedness, and washing on the diversity of hand surface bacteria. Proc. Natl. Acad. Sci, USA. 105: 17994-17999.