The right bacteria might help fight obesity

Different kinds of bacteria that live inside the gastrointestinal tract can help spur obesity or protect against it, according to scientists at Washington University in St Louis who transplanted intestinal bacteria from fat or lean people into mice and watched the rodents change. And what they ate determined whether the good bacteria could move in and do the job.

The study raises the possibility of one day turning gastrointestinal bacteria into personalised adiposity-fighting therapies, and it may help explain why some people have a harder time losing weight than others do.

"It's an important player," said Dr David Relman of Stanford University, who also studies how gastrointestinal bacteria influence health but wasn't involved in the new research.

"This paper says that diet and microbes are necessary companions in all of this. They literally and figuratively feed each other."

Washington University graduate student Vanessa Ridaura took