It’s hard to be sure of many things these days, but at least you can be certain that your cells are 100 percent human, right? Not so fast there, homo sapiens. “Only 10 percent of our cells are human. There are more bacterial cells than human cells in our body, and most our genes and DNA are bacterial,” says Ran Blekhman, an assistant professor who joined the College of Biological Sciences this fall.
Blekhman’s research, using information collected by the Human Microbiome Project, has led to some fascinating insights about the mysteries of the microbiomes that make up so much of who we are. “These bacteria have been linked to many diseases, such as diabetes, which have also been shown to have a genetic component,” says Blekhman. “My research examines how the microbiome is connected to the genes of a person, who is really a ‘host’ for the bacteria.”
In learning more about this symbiosis, Blekhman has produced one of the first studies documenting the relationship between microbiome composition and the human genome. “What we’ve been able to learn is that genetic variation in immunity genes is correlated to the composition of the microbiome” he says. His team found significant correlations in 10 of the 15 body sites that were sampled, including the gut, skin and mouth.
This is a very early step, Blekhman says, and there are no health-related implications to the research yet. The next phase will be to look at correlations for specific disease, beginning with colon cancer, since humans carry the largest number of bacteria in the gut. “We’re taking samples from colon cancer patients, both from their tumors and their healthy tissues, and comparing the microbiomes and gene expression in both locations. We just started this work a couple months ago, but hopefully we will have some initial results as early as next year,” he says.
Blekhman is one of the first researchers hired through a new “cluster hiring” initiative designed to bring scientists on board whose interests complement those of current faculty to form research clusters. Professor David Greenstein, who leads this year’s search committee, says that the focus of the initiative is to create centers of excellence in fields such as genomics, bioinformatics and computational biology. “Biologists have been slow to embrace computation, especially when compared to our colleagues in areas such as physics,” says Greenstein. “We really need a critical mass in these areas, and it will help us to have people like Ran who can navigate the world of biology and the world of computing.”