[arvin]

> Regarding the antibiotics, it's not completely clear why giving them to animals makes them bigger

From the 'Germs Are Us' article:

"In August, Ilseung Cho, of the New York University School of Medicine, published a study showing that antibiotics eradicated bacteria, commonly found in the digestive system of mice, that help the animals metabolize calories efficiently; without the microbes, the mice absorbed more calories from the same amount of food and rapidly became obese."

http://www.newyorker.com/reporting/2012/10/22/121022fa_fact_...