Removing gut bacteria may play critical role in reducing cancer risk

Bacteria in the gut are essential for the development of intestinal tumors in mice, according to research led by investigators from the Icahn School of Medicine at Mount Sinai. Removing the bacteria may play a critical role in reducing cancer risk, the researchers write, in the March issue of the Journal of Experimental Medicine.

Sergio A. Lira, MD, PhD, Director of the Immunology Institute, and Professor of Immunology and Medicine, and his laboratory at the Icahn School of Medicine at Mount Sinai, used a transgenic mouse model to test the hypothesis that distribution of intestinal polyps (precancerous lesions) was dependent on the bacteria (or microbiota) in the gut. They treated the mice with antibiotics to eradicate the populations of bacteria living in the gut. The treatment proved effective in preventing polyp formation. The authors propose that bacteria cross from the gut into the tissue of the intestinal wall, promoting inflammation and tumor growth.

"This begins to get at some of the nongenetic factors that spur the development of colorectal cancer," said Dr. Lira. "Understanding the interplay between genetic mutations, gut bacteria, and inflammation may lead to new diagnostics and treatments for intestinal cancer."