Biotechnologists have constructed an implantable genetic regulatory circuit that monitors blood-fat levels. In response to excessive levels, it produces a messenger substance that signals satiety (fullness) to the body. Tests on obese mice revealed that this helps them lose weight.
According to the WHO, over half the population in many industrialized nations is overweight, one in three people extremely so, with high-calorie and fatty food a lifetime on the hips, backside and stomach. This also leaves traces in the blood, where various fats ingested via food circulate — a risk factor for heart attacks and strokes.
The biotechnologists combined different genes* that produce particular proteins and reaction steps for several different saturated and unsaturated animal and vegetable fats. They implanted this genetic construct in human cells, inserted these cells into tiny capsules, and implanted the capsules in obese mice that had been fed fatty food.
Fix for mouse obesity now; humans will take longer
Result: the mice stopped eating and their body weight dropped noticeably. As the blood-fat levels also returned to normal, the regulatory circuit stopped producing the satiety signal.
“The mice lost weight although we kept giving them as much high-calorie food as they could eat,” said ETH-Zurich professor Martin Fussenegger from the Department of Biosystems Science and Engineering.. “The animals ate less because the implant signalized a feeling of satiety to them. Mice that received normal animal feed with low (five percent) fat content did not lose any weight or reduce their intake of food.”
Fussenegger envisages that one day obese people with a body mass index of way over thirty could have such a gene network implanted to help them lose weight — an alternative to invasive surgical interventions such as liposuction or gastric bands. “Instead of intervening in the progression of a disease that is difficult to regulate, it has a preventive effect and exploits the natural human satiety mechanism.”