Weight linked to type of bacteria in gut

Obesity doesn’t seem to be what it was previously thought. New studies and researches are indicating that a microbial component in the gut may be contributing to obesity and that overweight is not just eating too much and being lazy but something that could be caused by different viruses and microbes.

Scientists reported that treating weight loss with dietary reductions and exercise could be like treating all fevers with one aspirin and that identifying microbes that live in the gut and contribute to obesity could lead to new weight loss treatments.

A study showed that obese people as well as mice had more of one type of bacteria and less of another kind. The obese had more of a Firmicutes type and lower levels of Bacteroidetes family. However, it is not established yet if excessive Firmicutes levels makes you fat or if the fat people grow more of that type of bacteria.

In the study scientists used lean mice with no microbes in their guts. After having Firmicutes transplanted the mice became "twice as fat" and took in more calories from the same amount of food than mice with the more normal bacteria ratio. When it comes to people, the results were pretty much the same.

Before they started dieting, the obese study participants had about 3 % of Bacteroidetes bacteria in their guts. When the course of treatment was over and they reduced their weight to normal, the levels of Bacteroidetes were close to 15%.

Scientists are hoping that they will be able to fight obesity by changing the bacteria in the intestines and stomach.