A Breath Test for Obesity, too? Researchers Believe Concentrations of Hydrogen and Methane Gas Could Test for BMI

Just as new information has been coming out on how to detect lung cancer, heart disease and even diabetes by blowing air into a machine, some researchers are thinking this might be applied testing for obesity, too.

According to a new study in the April issue of the Journal of Clinical Endocrinology & Metabolism, the bacterial overgrowth that can be caught by a standard breath test may also reveal one's body fat percentage.

Apparently when one's microbiome (the complex infrastructure of good and bad bacteria that live in and on us) gets out of balance, with the bad bacteria outperforming the good, people can experience constipation, bloating, diarrhea, etc. Yet this new research finds that the imbalance also correlates with obesity, according to CNET.

"Normally, the collection of microorganisms living in the digestive tract is balanced and benefits humans by helping them convert food into energy," said lead author Ruchi Mathur at the Division of Endocrinology at Cedars-Sinai in Los Angeles. "When [the microorganism called Methanobrevibacter smithii] becomes overabundant, however, it may alter the balance in a way that makes the human host more likely to gain weight and accumulate fat."

They would specifically test for high concentrations of hydrogen and methane gas through the test, which researchers believe could indicate information from the colonized digestive track.

In this study, almost 800 participants had their body fat measured using BMI (which looks at height and weight) and low-wattage electrical conductivity (which differentiates between fat and lean tissue). They then drank a sugary syrup and took a breath test every 15 minutes for two hours.

Those with higher BMIs and more body fat exhaled higher levels of methane and hydrogen, while those with lower BMIs and body fat had either lower levels of each gas or a higher concentration of only one of the two gases.

Mathur said obesity is not a one-size-fits-all disease, but looking for methane and hydrogen concentrations in one's breath could help identify whether an obese person may be more likely to respond to specific weight loss programs.

However, researchers note that as to whether modifying the bacteria in the gut will help anyone lose weight faster or easier could still be debated and needs to be researched through further studies.