Spring 2010: Of Note
What’s in Your Digestive Tract?
By Quinn Eastman
Hungry? Don’t feel too guilty.
Your appetite could be spurred by intestinal bacteria, according to Emory researchers. Increased appetite and insulin resistance can be transferred from one mouse to another through intestinal bacteria, says a study published in March by Science magazine. The finding bolsters previous evidence that these bacteria can contribute to human obesity and metabolic disease.
“It has been assumed that the obesity epidemic in the developed world is driven by an increasingly sedentary lifestyle and the abundance of low-cost, high-calorie foods,” says Andrew Gewirtz, associate professor of pathology and laboratory medicine at Emory’s School of Medicine, who authored the paper with pathology instructor Matam Vijay-Kumar. “However, our results suggest that excess caloric consumption is not only a result of undisciplined eating, but that intestinal bacteria contribute to changes in appetite and metabolism.”
The researchers studied mice engineered to lack a substance in the intestine known as TLR5 that senses and controls bacteria. Compared to mice that have TLR5, they were found to be about 20 percent heavier and show characteristics of metabolic syndrome, a cluster of disorders that in humans increases the risk of developing heart disease and diabetes.