An important and exciting piece of research just came out in Science Magazine last week showing why gastric bypass surgery has such powerful curative effects on diabetes, beyond the previous belief that the dietary restriction helps diabetes. This is critical as it suggests that it is the physical reorganization of the gut, and not the change of diet modify glucose metabolism and lead to remission in diabetes. This new work caps a series of research over the last several years that led to my own gastric bypass 5 months ago. As a physiologist I was puzzled, in my discussions with my surgeons and in my reading of the literature, why patients commonly go into the hospital for surgery as diabetes, and leave a few days later in full remission. Surely, if it was the case that the dietary restriction caused this, the obvious treatment for diabetes would be to starve yourself for a few days the minute you were diagnosed. But it doesn’t work, so dietary restriction cannot explain the effects of the surgery either.

The surgery, which reduces the stomach to about the size of an egg, rearranges the intestines into the shape of a Y. Nicholas Stylopoulos, of Boston Children’s Hospital in Massachusetts, led his team to perform the surgery on obese and non-obese diabetic rats, and then watched for changes. They found that Roux-en-Y-treated rats increased ingestion of sugar. As a result, the intestine became a major source of whole-body glucose control.

With the new animal model in hand, researchers can now determine exactly what happens in the surgery to accomplish this, and they can potentially develop pharmaceuticals to accomplish the same effects, and, hopefully, cure type II diabetes in the future without surgical intervention.

In the meantime, the research validates the important, and perhaps uniquely curative, role that gastric bypass plays in controlling diabetes. It is a heavy blow to pundits who claim that the only role of the surgery is to restrict diet, and that it is therefore fundamentally unnecessary.