Digestive-Tract Bacteria linked to Obesity

Differently structured microorganisms inhabit in intestines of obese people which makes them gain weight, researchers of a new study have shown.

The digestive system of every person is home to a unique concoction of trillions of bacteria and other minute microorganisms that help to break down food and glean energy.

The researchers of the new study are of the view that the microbes present in obese people are better at the process of breakdown and extract more energy than what slim people derive from the same amount of food, which in turn are sucked up by the body and deposited as excess fat.

Lead author of the study, Jeffrey Gordon at the Washington University School of Medicine in St Louis, aptly said, "Minor differences in the calories you can harvest might play an important role in predisposition to obesity."

As per the study, researchers examined stools of 12 willing obese volunteers and compared them with those of five slim volunteers.

Genetic sequencing used to identify the different species of bacteria in there, researchers found that most of the bacteria fell into two groups, called Firmicutes or Bacteroidetes.

However,stools of obese volunteers showed 20 percent more Firmicutes bacteria and nearly 90 percent less Bacteroidetes bacteria compared to the slim ones.

As an extended part of the study, the obese volunteers were shifted on a low-fat and low-carbohydrate diet for one year.

Along with losing as much as 25 percent of their body weight, obese volunteers also showed a dropped proportion of Firmicutes and a raised level of Bacteroidetes in their stools on year end examination.

Citing weight gain as a vicious process, obesity can upset the normal microbial balance in the body which in turn shows up with an increased activity of microbes.

But the researchers believe that the other way round is also true; shifting the microbes also affects weight.

To prove this, researchers sucked microbes from the intestines of both lean and obese mice.

These microorganisms were then injected into the intestines of mice.

After two weeks, the mice injected with the ‘obese’ microbes reported a nearly double increase in the quantity of fat than those that received the 'thin' microbes.

While the implication of the finding is, for now, unclear, it could potentially lead to new treatments for overweight people.