BBC News – Bacteria find key to treating obesity without surgery
In the latest study, researchers compared three groups of obese mice on a high-calorie diet.
- One group was given a gastric bypass
- One was given a sham operation, and the high-calorie diet continued
- One was given the same fake operation but then fed a low-calorie diet to promote weight loss
A week later the mice who had undergone the real obesity surgery had different bacteria in their guts, with an increase in types usually seen in lean individuals and a drop in types associated with obesity.
Three weeks after surgery they had lost about 30% of their bodyweight, the researchers reported in Science Translational Medicine.
There was little change in micro-organisms present in the mice who had had sham operations, even though the group on the low-calorie diet lost just as much weight as the mice who had had the bypass surgery.
Researchers then transferred samples from the guts of the three groups of mice into other germ-free mice.
Those who received bacteria from the bypass mice, lost a significant amount of weight in two weeks but the others saw no change.
It is not yet clear how the microbes influence weight loss, but one theory is that they have an impact on metabolism.