{New Study Shows} Gut Bacteria is Keeping The Gut Up

A new animal study published in this month's issue of the Journal of Proteome Research suggests that bacteria living in the large intestine may play a role in obesity by slowing down the activity of energy-burning brown fat. The researchers said their findings could spur new ways to prevent obesity and promote weight loss, for example by pointing to new drug targets and microbial treatments.

There are two types of fat or adipose tissue in the body: brown fat and white fat. Brown fat burns calories when stimulated (it even burns white fat), while white fat stores energy (calories) and makes hormones.

Brown fat exists in small deposits in the neck area and elsewhere, whereas white fat deposits as flab around the waist and buttocks.

Everyone has both brown fat and white fat, but the amounts vary. Recent evidence suggests thin people have more brown fat than overweight and obese people. Young, healthy women have the most brown fat, while overweight adult men have the least.

In healthy humans, like other mammals, the large intestine is home to trillions of bacteria that help digest food and do other essential things like make vitamins.

Recently we have discovered that gut bacteria also interact with the rest of the body in some surprising ways, for instance they fine tune the immune system, and influence how we use and store energy.

And this is the first study to examine if gut bacteria influences brown fat, said the researchers, from Imperial College, London, UK, and the Nestlé Research Centre in Lausanne, Switzerland.

They ran a series of experiments where they compared regular mice with normal gut bacteria, and "germ-free" mice, bred to lack bacteria in their large intestine.

They found that brown fat in the germ-free mice appeared to be more active and burned calories faster than in the regular mice.

They also found that large-intestine bacteria seemed to be associated with gender differences in weight. br>
Regular male mice were heavier and fatter than their female counterparts, but there were no such differences in the bacteria-free mice.

And they noticed major differences in the interactions between male and female mice and their intestinal bacteria that might shed light on why the obesity epidemic is developing faster in women.

One theory the researchers proposed, was that gut bacteria contribute to host energy metabolism by producing short chain fatty acids through the fermentation of carbohydratesthat would remain undigested if they weren't present.

When the bacteria are not there, the short chain fatty acids are not produced, and this disrupts a number of metabolic processes, thereby triggering calorie burning (lipolysis activity) in both the brown fat and the liver.

The researchers suggest their findings could help find new ways to treat or prevent obesity, for instance by boosting the energy burning activity of brown fat.

The study was funded by Nestlé as part of the Imperial College London-Nestlé strategic alliance.

Written by Catharine Paddock PhD
 Medical News Today