Image may be NSFW.
Clik here to view.
Every person carries around millions of bacteria in their guts, which help maintain a healthy colon and digestive system, and may even prevent colon cancer. But they aren't all good.
Researchers have found that some of the bacteria in the gut may be making you fat.
In a paper published in the September 2012 issue of the journal Cell Host and Microbe researchers from the University of North Carolina have identified a type of bacteria that increases the amount of fat and calories the intestines of zebrafish can absorb.
(Zebrafish were used because they are nearly transparent when they are young, so it's easy to see inside their guts.)
They were fed fatty acid molecules tagged with a florescent dye to observe the fat absorption. Zebrafish with the bacteria got more calories from the same diet than zebrafish without this bacteria.
Although this study was performed in zebrafish, previous research in humans found correlations between relatives of this bacteria and obesity.
Luckily, we can change the kinds of microbes that live in our guts: The researchers also found that the populations of this bacteria were influenced by diet. Fattier diets promoted larger populations of Firmicutes which would then lead to more fat absorption. The increase of this bacteria is reversible by following a low-fat diet.
Some research has shown that you can also increase your "good" gut bacteria by taking probiotics — bacteria in the form of supplements and even yogurt.
