March 26, 2013
Obesity Breathalyzer? Study Finds Link Between BMI And Gases In The Breath
Brett Smith for redOrbit.com - Your Universe Online
Law enforcement has been using breathalyzers for years to protect the public from drunk drivers, but a new study from Cedars-Sinai Medical Center in Los Angeles suggests that breathalyzers might serve to protect certain people from doughnuts and other fatty foods.
According to the study, which appeared in the“¯Journal of Clinical Endocrinology & Metabolism, someone with a higher body mass index (BMI) is associated with higher concentrations of hydrogen and methane gas in their breath. These gases are associated with a methane-producing intestinal microorganism called Methanobrevibacter smithii (M. smithii).
"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 Dr. Ruchi Mathur, director of the hospital´s Outpatient Diabetes Treatment and Education Center in the Division of Endocrinology. "When M. 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."
In the study, researchers analyzed the breath-chemical content of over 790 people. An analysis of the breath showed four different patterns: normal breath content, higher levels of methane, higher concentrations of hydrogen, or higher levels of both gases. Participants whose breath test contained higher concentrations of both gases tended to have a higher BMI and higher percentages of body fat.
"This is the first large-scale human study to show an association between gas production and body weight — and this could prove to be another important factor in understanding one of the many causes of obesity,” Mathur said.
As M. smithii metabolizes hydrogen in the digestive tract it produces methane, which is eventually exhaled by the individual. The scientists say this bacterial action allows for a more efficient extraction of nutrients from food — resulting in a greater risk of weight gain and obesity for the human host.
"Essentially, it could allow a person to harvest more calories from their food," Mathur said.
It should be noted that Mathur´s connection between bacterial action and obesity is only a theory and the study did not establish a concrete causal relationship between the two. Previous research has shown conflicting evidence on the relationship between M. smithii and body fat.
A June 2012 article published in the International Journal of Obesity by a group of French researchers found that obese individuals were associated with the intestinal microbe“¯Lactobacillus reuteri and lower levels of“¯M. smithii. And a 2009 study in the journal PLOS ONE by the same research group found that high levels of“¯M. smithii were associated with“¯anorexia.
Despite some conflicting evidence, Mathur continues to explore the potential connection between M. smithii and body fat. She is currently working on a study that looks at the effects of targeting the bacteria with a specific antibiotic.
"We're only beginning to understand the incredibly complex communities that live inside of us,” she said. “If we can understand how they affect our metabolism, we may be able to work with these microscopic communities to positively impact our health."