A New Type of Bariatric Surgery Improves Blood Sugars for Type 1's

Researchers at the Toronto General Hospital Research Institute led by Dr. Tony Lam and Dr. Danna Breen, used a rat model to study novel nutrient-sensing signals in the jejunum, located in the middle of the intestine.

Dr. Lam and his team demonstrated that duodenal-jejunal bypass surgery activates novel nutrient-sensing signals in the jejunum and rapidly lowers blood sugar levels in non-obese rats with uncontrolled diabetes.

DJB surgery is a type of bariatric surgery, which excludes the duodenum and proximal jejunum, the first section of the small intestine, and instead redirects food into the distal jejunum, the middle to last section of the intestine.

This latter section of the intestine, as demonstrated by Dr. Lam and his team, can sense glucose and signal to the brain to let the liver know that it must lower glucose production, leading to better control of blood sugar in the diabetic rats.

The study showed for the first time that a surgical intervention induces a rapid glucose-lowering effect in non-obese type 1 uncontrolled diabetic rats, independent of a reduction in food intake and body weight as well as changes in blood insulin levels.

"We report that shortly after a meal, the influx of nutrients into the jejunum of DJB surgical diabetic rats activates novel sensing mechanisms to lower blood sugar levels. Importantly, this occurs in the presence of insulin-deficiency and is independent of weight loss," explained Dr. Lam.

Many laboratories around the world are in a race to find alternative and effective ways in which to lower and better control glucose levels because of the severe complications, which can result from high sugar levels. Dr. Lam's laboratory is a world pioneer in exploring the role of the gut in regulating blood sugar.

"The gut is an easier and therefore more promising therapeutic target in regulating blood sugar than the brain or liver, due to their potential side effects," said Dr. Danna Breen, who is the lead author in the study.

Dr. Breen added that this type of surgery may potentially have therapeutic value in lowering glucose (sugar) levels in non-obese individuals with type 2 or 1 diabetes, but that many more years of future studies are required to determine whether this approach is effective and safe in humans who have diabetes.

Published in the May 20, 2012 on-line edition of the international journal Nature Medicine. (ANI)