Is anti-obesity contagious?

 28 April 2012 (NewScientist):

In 2006, biologists found that the types of bacteria in the guts of obese rats differed from those in non-obese rats. To find out more, Mihai Covasa and his colleagues at the French National Institute for Agricultural Research (INRA) in Paris swapped gut bacteria between obesity-prone and obesity-resistant rats.

The obesity-resistant rodents proceeded to eat more and pile on the pounds. They also developed gut hormone levels typical of obesity-prone rodents.

To treat obesity, it should possible to move the bacteria the other way around, from obesity-resistant individuals to obesity-prone ones.