It's not your fault that you are fat. It's your bugs.

Well I'll be bug_____!

It appears that the presence of certain forms of internal parasites cause a predisposition to obesity. if that is so, just how much does that explain for all those poor people who just can't get weight off. The clincher in the research here is that when the bugs in question were transferred from one obese mouse to another slim mouse; the slimmy became the fatty.

Here's the article from the LA Times.