The human body contains billions of microorganisms. Microbial cells in the human gut are estimated to outnumber human cells by ten to one in healthy adults, according to the National Institutes of Health (NIH), but very little is known about the ways in which these minute life forms influence health and disease.
A new molecular ecology facility at George Mason University, the MicroBiome Analysis Center (MBAC), is attempting to scout this unchartered territory and map the world that these bacteria, viruses, fungi and protozoa inhabit within us. Their effect on human health will be a major focus of research at the center where investigators will explore microbial imbalances on or within the gut, mouth, respiratory tract and urinary and reproductive systems.
"It's a new tactic to actually characterize the human microbiome or population of microorganisms living within the human body and try to correlate it with disease states and changes within the immune system," says Patrick Gillevet, the MBAC's director and associate professor in Mason's Department of Environmental Science and Policy. "This center will allow us to sequence and characterize these microorganisms in order to study their relationship to diseases such as obesity, cancer and irritable bowel syndrome."
Gillevet, who has been studying the genes of microbes at Mason since 1998, developed and patented a technology for genomic sequencing in 2006 called Multitag Pyrosequencing (MTPS) that allows researchers to examine, count and barcode hundreds of thousands of microorganisms per day within samples taken from various ecological systems including the human body. MTPS will serve as the backbone of the center's research efforts.
"Multitag Pyrosequencing is revolutionizing the study of microbial communities," says Gillevet. "Before this technology was developed, we would have been hard-pressed to identify a couple hundred of microbes per sample. Now, we are identifying 50,000 or 60,000 microbes per sample. We can literally do in an afternoon what it took us 10 years to do in the past."
Supported by more than one million dollars in grants from the Department of Defense and NIH, Gillevet's team is currently collaborating with researchers at Rush University Medical Center in Chicago to chart the presence of microorganisms in patients suffering from breast cancer, Crohn's Disease, inflammatory bowel disease, cirrhosis of the liver and HIV.
A large dilemma the center will look at is the correlation between a patient's disease and the types and quantities of microbes in his or her body.
"We need to figure out what came first, the chicken or the egg," says Gillevet. "Did the bacteria change and upset the immune system and cause the cancer? Or did the cancer start, upset the immune system and then upset the bacteria? Or did the immune system get upset and affect both? That's what we're trying to find out."
He believes that the answer lies in computational science and has partnered with John J. Grefenstette, professor in Mason's Bioinformatics and Computational Biology Department, and Huzefa Rangwala, assistant professor in Mason's Department of Computer Science, in order to develop software that will bridge this gap between ecology and medicine.
"It is clear from the current literature and our own collaborative work that the bacterial community in the gut is intimately connected to the immune system function and health of the human organism," says Gillevet. "Finding the microbes responsible for particular diseases may increase the likelihood of developing new diagnostic tests and treatments for them."
About George Mason University
Named the #1 national university to watch by U.S. News & World Report, George Mason University is an innovative, entrepreneurial institution with global distinction in a range of academic fields. Located in the heart of Northern Virginia's technology corridor near Washington, D.C., Mason prepares its students to succeed in the work force and meet the needs of the region and the world. With strong undergraduate and graduate degree programs in engineering and information technology, dance, organizational psychology and health care, Mason students are routinely recognized with national and international scholarships. Mason professors conduct groundbreaking research in areas such as cancer, climate change, information technology and the biosciences, and Mason's Center for the Arts brings world-renowned artists, musicians and actors to its stage.