Salmonella, which is generally contracted from contaminated poultry, meat, eggs, or water, affects the intestinal tract.

CNN: STORY HIGHLIGHTS

The intestinal tract is host to a number of microbes, mostly bacteria that are needed for good health.

CNN: Could I become dependent on probiotics?

Acidophilus kills the harmful bacteria strain of E. coli in the intestinal tract.

FORBES: Connect

They simulated the human digestive process by subjecting the tissue to treatment with the same digestive fluids they would encounter in the intestinal tract.

BBC: Prions damage brain tissue

The researchers will test the participants' glucose tolerance, the time it takes for digested food to transit through the intestinal tract, and the amount of calories in the patients' stool.

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?

It's also possible, says Mathur, that the release of methane slows the transit of digested food through the intestinal tract, and that could increase the time for additional calories from digested food to be absorbed and added to the body's tally.

CNN: Can you smell obesity?