13 Dec 2012 The Bypass Cure
Type 2 diabetes can be reversed in the operating room. The implications are staggering for halting one of the world’s deadliest diseases.
In March of last year, the International Diabetes Federation endorsed bariatric surgery as a type 2 diabetes treatment for obese patients, citing studies indicating that it triggers remission in about 85 percent of patients.
Bariatric surgery is the umbrella term for all weight-loss surgeries reserved for obese patients. Gastric bypass is a subset of these surgeries that first divides the stomach into a small and large pouch and then connects the small stomach pouch to the lower small intestine; Roux-en-Y is the most popular gastric bypass surgery in the group.
The federation’s endorsement was an extraordinary validation of decades of research and medical experience showing that surgery to reduce food intake can alter the biochemistry of the entire body. It also marked the beginning of a major new assault on diabetes.
There are over 200 hormones in the GI tract. All of those hormones are vying to control your eating behaviour. Ghrelin drives the urge to eat. Stretch receptors in the stomach signal when to stop. This hardwired system worked well for our hunter-gatherer ancestors constantly struggling to find enough food for survival. In the modern world — where cheap, high-calorie food is available all around — taste, smell, emotion, learning, memory, and food addiction tend to override our biological cues and entice us to eat even when there is no need.
“We are living in a time of overabundance, and we are engineered to hold on to these calories. It’s like a trap,” says bariatric specialist surgeon, Dr Julio Teixeira.
Surgeon-scientists like Teixeira are seeking biological manipulations that will help set us free. His work focuses on changing the architecture of the stomach and rerouting the small intestine, which is an exceedingly complex organ — hardly a homogeneous, 23-foot pipe carrying food from the stomach to the large intestine, as was once believed.
There are three sections of the small intestine, each lined with unique cells that secrete their own hormones and play distinct roles. If you chop out or bypass certain sections, then, particular hormones can be reduced or eliminated.
The first and shortest section of the small intestine, just under one foot long, is the duodenum, which connects directly to the stomach. The duodenum blends partially digested food with bile, a bitter yellow-green liquid made in the liver that helps digest fats.
From there the food passes through the eight-foot midsection of the small intestine, the jejunum, where fingerlike projections absorb vital sugars, amino acids, vitamins, and small proteins.
The final stretch of small intestine, the ileum, secretes incretins and absorbs more nutrients before emptying into the large intestine for elimination. By cutting and pasting these intestinal links into new configurations, Teixeira can profoundly reconfigure the body’s chemistry.
The more than 200 000 gastric bypasses performed in the United States each year can offer only limited help for the 25 million diabetics in this country alone. The challenge is even greater in the global context: The International Diabetes Federation estimates that by 2030, some 439 million people worldwide will have type 2 diabetes.
Lack of insurance and patients’ reluctance to undergo an operation also make bypass surgery an unlikely cure-all. But now that researchers are beginning to understand what Teixeira calls the “magic” of gastric bypass, they are aiming to find a chemical treatment that does the same thing.
“We can probably figure out exactly why bariatric surgery triggers remission and develop the medicine to stop diabetes,” says Walter Pories, chief of surgery at East Carolina University’s Brody School of Medicine, who first showed that the illness vanished after such operations. “Then we don’t need surgery.”