M. smithii harvests hydrogen molecules from neighboring microbes in the gut, which it then transforms into methane gas.

CNN: Can you smell obesity?

It's that smaller group of individuals who might be genetically predisposed to harboring levels of M. smithii that might put them at higher risk of developing obesity.

CNN: Can you smell obesity?

The culprit, she believes, is a member of archaea known as Methanobrevibacter smithii, which is present in the intestinal tract of about 70% of people, but elevated in about 30%.

CNN: Can you smell obesity?

In order for M. smithii to thrive, it needs the hydrogen from surrounding microbes, and that may be why people with higher levels of both hydrogen and methane gases in their breath were heavier than those with elevated levels of methane or hydrogen alone.

CNN: Can you smell obesity?

Then the volunteers will be given an antibiotic to essentially wipe out the population of M. smithii and the same parameters will be measured again, to see if eliminating the microbes will help change the patient's weight profile and alter their trajectory toward diabetes.

CNN: Can you smell obesity?

She is also studying a group of children to see how early M. smithii buildup occurs, and how soon in development it starts to set up a pattern of weight gain that might then be interrupted by changing the composition of the gut microbial world.

CNN: Can you smell obesity?

For those whose weight gain may be due in part to the activity of M. smithii, controlling the organisms with antibiotics or other medications could slow down the rate at which they pack on the pounds, and these individuals could easily be identified with a relatively simple breath test.

CNN: Can you smell obesity?