Antibiotics linked to fat buildup

Antibiotics may plump up cows, pigs, chickens, mice and humans alike, new research suggests.

For decades, low doses of antibiotics have been given to livestock to make the animals grow and bulk up faster, but no one really knew how the drugs promoted growth. Now, researchers led by microbiologist Martin Blaser at the New York University School of Medicine report online August 22 in Nature that antibiotics alter the mix of bacteria in the intestines of mice and cause the rodents to build up more fat than normal.