Are Antibiotics Partly To Blame For Obesity Epidemic?

This morning's On Point with Tom Ashbrook raised a critical question: might antibiotics be "a scale-tipping X-factor" driving the American obesity epidemic?

Featuring reporter Pagan Kennedy, who just wrote a piece on this topic, "The Fat Drug," for the New York Times Magazine, and researcher, Dr. Illseung Cho, with the New York University School of Medicine, author of a recent Nature article on antibiotics' impact on the microbiome, the radio segment explored the possibility that missing microbes in our gut might be party responsible for our growing weight.

Who knew, for instance, that a single course of antibiotics can potentially alter your gut bacteria forever?

Here's more from Kennedy's report:

American kids are prescribed on average about one course of antibiotics every year, often for ear and chest infections. Could these intermittent high doses affect our metabolism?

To find out, Dr. Blaser and his colleagues have spent years studying the effects of antibiotics on the growth of baby mice. In one experiment, his lab raised mice on both high-calorie food and antibiotics. “As we all know, our children’s diets have gotten a lot richer in recent decades,” he writes in a book, “Missing Microbes,” due out in April. At the same time, American children often are prescribed antibiotics. What happens when chocolate doughnuts mix with penicillin?

The results of the study were dramatic, particularly in female mice: They gained about twice as much body fat as the control-group mice who ate the same food. “For the female mice, the antibiotic exposure was the switch that converted more of those extra calories in the diet to fat, while the males grew more in terms of both muscle and fat,” Dr. Blaser writes. “The observations are consistent with the idea that the modern high-calorie diet alone is insufficient to explain the obesity epidemic and that antibiotics could be contributing.”