Obese people have a 50 percent greater chance of developing intestinal cancer than people who are lean. A study conducted by doctors and researchers at Thomas Jefferson University, Duke Medical School and Harvard Medical School found that intestinal cancer in obese people is caused by the switching-off of a hormone named guanylin. The study also suggests that such cancer in obese people can be treated by replacing the lost guanylin hormone using hormone replacement therapy.

The study, published in the medical journal Cancer Research, used genetically modified mice to conduct experiments to investigate this matter. To simulate a virtual situation that would be comparable to the situation in a human body, they first fed the mice additional calories to make it obese. They then observed the impact of the additional calories on the guanylin hormone in the epithelium. They noticed that this hormone did switch off just as it had in the cancers in the intestines of obese people. When the hormone switched off, it led to the epithelium losing it's ability to balance and regenerate its cells, and therefore failing in its function. This allowed the development of the cancer as the body's mechanism to control and fight it was thwarted.

In the same mice, when researchers replaced the lost guanylin with a fresh dose of the same hormone and saw that the function of the hormone and epithelium was restored again. The researchers expect that the data from the study can be implemented to help obese people fight intestinal cancer.

Dr. Scott Waldman, the chair of Pharmacology and Experimental Therapeutics at Thomas Jefferson University's Sidney Kimmel Medical College, said: "The beauty of our findings is that while we know the hormone is lost in the obese mice, its receptors are just sitting there waiting to be switched on. And this study demonstrates that if you can prevent hormone loss, you can also prevent tumor development," according to a press release concerning the study.