Gastric Bypass Surgery And Type 2 Diabetes

Boston Children's researchers linked the small intestine's role post-surgery to the elimination of type 2 diabetes.

Although it was previously assumed that the weight loss which followed a gastric bypass procedure eliminated type 2 diabetes, a research team from Boston Children’s Hospital announced last week that it’s actually changes in the small intestine post-surgery that often resolve type 2 diabetes.

The study, which was published last month in the journal Science, was an effort to investigate why type 2 diabetes is often resolved by gastric bypass surgery before weight loss has even occurred. Type 2 diabetes affects 25.8 million Americans, and is found largely in adults, according to Boston Children’s Hospital. Obesity and struggles with metabolism are often closely tied to type 2 diabetes, and diabetes is the seventh leading cause of death in the U.S.

For this study, the Boston Children’s research team spent a year studying rats, and observed that after gastric bypass surgery, the small intestine changed in the way that it processed glucose. The intestine used and disposed of glucose after surgery, thereby regulating glucose levels in the rest of the body and helping to resolve type 2 diabetes. Previous to this discovery, most doctors and scientists believed that gastric bypass surgery resolved diabetes because the surgery caused weight loss, but this research proves that there are other factors at play even before weight loss occurs.

“We have seen type 2 diabetes resolve in humans after gastric bypass, but have never known why,” says Dr. Nicholas Stylopoulos, the study’s lead researcher, in a Boston Children’s report. “People have been focusing on hormones, fat and muscle, but we have shown in this study that the answer lies somewhere in the small intestine most of the time.”

Gastric bypass surgery is a weight loss treatment typically used only with individuals who are severely obese. The procedure reroutes food into a smaller pouch in the stomach, leading to extreme weight loss. After the surgery, Stylopoulos and his team found that the intestine reprograms itself to regulate glucose, which is an imperative function needed to eliminate diabetes.

In the study, Stylopoulos also found that type 2 diabetes was resolved in 100 percent of the rats that underwent gastric bypass surgery. And 64 percent of those cases were resolved because of the changes that occurred in the small intestine, and the other 36 were likely resolved because of weight loss or other factors, according to the study. These findings will hopefully help other researchers mimic the small intestine’s reprogramming, but without surgery.

“With further research, we may find ways to bypass the bypass,” Stylopoulos said in the Boston Children’s report. “The results of our study are promising because, unlike the brain and other organs, intestines are easily accessible. Furthermore, since cells in the intestine have such a short lifespan, we can easily study and pharmacologically manipulate them to use glucose, without long-term problems.”