Why does obesity raise the risk of developing cancer? A new study suggests that the wrong mix of gut bacteria could be to blame. Researchers report that obese mice carry altered communities of intestinal bugs, which produce DNA-damaging acid that leave the mice more susceptible to liver cancer. The findings hint that bacteria help drive cancer development and may eventually help scientists better predict and prevent the disease.
Obesity increases the odds of falling victim to certain types of cancer, including colorectal and liver tumors, but scientists haven’t been able to identify the mechanism behind this link. They’ve suspected that our gut microbiota—the complex community of trillions of microbes living in our intestines—play a role. After all, gut bugs have been linked to other diseases, including inflammatory bowel disease, allergies, and even heart disease, and are known to differ between lean and obese individuals.