Gut Bacteria Cause Obesity, Not Just Gas

A common gut bacteria species that causes unpleasant gas may be linked to the rising obesity epidemic as well. A new study performed at Cedars-Sinai Hospital in Los Angeles showed that people who have higher levels of gas also tend to be more overweight.

The study, published late last week online in The Endocrine Society’s Journal of Clinical Endocrinology & Metabolism, reported that the doctors measured the breath of 792 people. Some people had normal breath, some had elevated amounts of hydrogen on their breath, some had too much methane, and some people had both gases.

The people who exhaled both gases were much more overweight, with a significantly higher body mass index (BMI).

Lead author Dr. Ruchi Mathur blamed one culprit, an unpleasant gut bacteria that’s responsible for most of the methane created by the human body. This hissable villain is called Methanobrevibacter smithii or M. smithii for short.

Digesting food isn’t something anyone does alone. Our gut bacteria help us break down the food we eat. However, when you have too much M. smithii in your gut, you don’t just produce a lot of extra gas. You may also digest your food differently, apparently in a way that causes victims to gain more weight than normal.

The worldwide obesity epidemic has baffled observers. An eight-year study performed in Shanghai, China and released late last year also linked gut bacteria with obesity.

In the Chinese study, rats didn’t get fat even if they were overfed on fat and denied exercise. They had to be exposed to the bacteria to pack on the weight.

A British biologist, David Weinkove, explained why it’s important to investigate the theory: “If obesity is caused by bacteria, it could be infectious.”

Could the nefarious activities of gut bacteria explain why you can’t lose weight?

[bacteria photo courtesy US Department of Agriculture]