(Nov. 9th, 2009) You're not alone! 100 Billion microbes colonise your body. So, do you think: Yuck! Or do you find your microbiota fascinating?
Who in the world wants to know exactly what creeps and flies between our fingers or hairs, under toenails, in ear canals or through our guts? Scientists stop at nothing. Some brave researchers from the University of Colorado at Boulder and the Washington University School of Medicine in St. Louis have picked at all the body’s orifices, taking samples from forearms and palms, armpits and behind the knees. Using high speed and high-capacity sequencing they claim to have identified all the microbes colonising both our interior and exterior.
Altogether the scientists detected 22 bacterial phyla and found that each habitat harbored its own characteristic set of microbes. Propionibacterinae prefer living on the forehead and on the nose. Staphylococcus ssp. linger in armpits and under the soles of the feet. The highest levels of variability within individuals over a three month time period occurred at specific skin sites like hair, nostrils and the ear canals. Surprisingly, the human mouth is the biotope displaying the least variation in diversity.
So, why do we need to know who lives with us? "We have an immense number of questions to answer," said Noah Fierer, a co-author on the study, who is an assistant professor in CU-Boulder's ecology and evolutionary biology department. "Why do healthy people have such different microbial communities? Do we each have distinct microbial signatures at birth, or do they evolve as we age? And how much do they matter? We just don't know yet."
Anyone who is particularly curious and beyond disgust may read further details in Science Express from November 5th, 2009.
Karin Hollricher