Wednesday, 15 May 2013

Can Gut Bacteria Trigger Weight Loss?

Our large intestine is home to trillions of bacteria. In fact, scientists say that we have ten times more bacterial cells in our body than human cells. Bacteria cells are much smaller than human cells and are found in our body cavities, such as the digestive tract. Many of the bacteria that share our bodies with us help us in some way, such as by digesting our food for us, producing vitamins that we use and boosting our immune system. Recently it's been proposed that the composition of our intestinal flora may be one factor that controls obesity. Intriguing new evidence suggests that adding a particular bacterium to our large intestine might help to regulate our weight.

Specific gut bacteria may help us lose weight.
Photo by clarita at
Professor Patrice Cani, Professor Willem de Vos and other researchers studied the effect of a bacterium named Akkermansia muciniphila on mice. Feeding the bacterium to obese mice not only caused the mice to lose weight but also reduced their insulin resistance. Insulin resistance is a condition in which the mouse or human body no longer responds properly to the presence of insulin. It's often a precursor to type 2 diabetes. 

The obese mice lost about half their weight after the addition of the bacterium, even though their diet wasn't changed in any other way. The researchers also found that feeding the mice a type of fiber known as oligofructose caused their population of Akkermansia muciniphila to increase.

The scientists discovered that Akkermansia muciniphila offered other advantages to the mice, too. It caused the mucus lining of their intestine to thicken. The mucus protects the intestinal lining, which is underneath the mucus, and also stops some substances in the intestine from entering the blood. Another very interesting discovery was that the presence of the bacteria caused different signals to be sent from the digestive system. These new signals altered the way in which fat was processed in the body. 
Akkermansia muciniphila was only discovered ten years ago. It lives in humans as well as mice and inhabits the mucus layer lining our gut. Scientists have discovered that the population of this bacterium is low in people suffering from obesity or inflammation and higher in people who don't have these conditions. The decrease in the bacterial population may be the result of the health problems instead of the cause. However, the other research performed with the bacterium suggests that it does play a role in weight loss.

Research in mice is often applicable to humans. Clinical tests using Akkermansia muciniphila in humans haven't been done yet. The potential uses of this bacterium are very exciting, though. The discoveries don't remove the need for overweight people to follow a sensible diet and exercise program, but the bacterium may be a wonderful aid to weight control in the future.