Microbes from bypass-treated obese mice may cause weight loss when transferred to lean mice. | Oak Ridge National Laboratory/US Department of Energy/Science Photo Library
Gastric bypass surgery, in which the stomach is stitched into a tiny pouch, has long been seen as a last resort for the dangerously obese. Doctors attributed rapid post-surgical weight loss to reduced hunger and restricted eating resulting from the smaller stomach.
But new evidence suggests weight loss may result when the procedure alters the types of microbes in the gut.
Scientists reached this conclusion by transferring microbes from bypass-treated obese mice to a group of lean mice raised in sterile conditions that left them with no intestinal bacteria at all. Two weeks after the transfer, recipient mice had lost considerable weight; another group that received microbes from obese mice in a placebo group — undergoing surgery without gastric bypass — stayed the same.
The new ...
