The crook of your elbow is not just a plain patch of skin. It is a piece of highly coveted real estate, a special ecosystem, a bountiful home to no fewer than six tribes of bacteria. Even after you have washed the skin clean, there are still one million bacteria in every square centimeter.
But panic not. These are not bad bacteria. They are what biologists call commensals, creatures that eat at the same table with people to everyone’s mutual benefit. Though they were not invited to enjoy board and lodging in the skin of your inner elbow, they are giving something of value in return. They are helping to moisturize the skin by processing the raw fats it produces, says Julia A. Segre of the National Human Genome Research Institute.
Dr. Segre and colleagues report their discovery of the six tribes in a paper being published online on Friday in Genome Research. The research is part of the human microbiome project, microbiome meaning the entourage of all microbes that live in people.
I think a microbiome project is a great idea. In medical school, we learn about the most common and/or most virulent bugs, but often on clinics I have noticed pathology reports come back with bugs I have never heard of, and wouldn't know how to categorize without the helpful notes from the pathologist. Having a better understanding of all the 'commensuals' can only help to improve not only medical school education but medical knowledge overall.