Bacteria living within the gut could have a link to obesity, possibly explaining how antibiotics fatten farm animals, and humans as well, and predispose some organisms to obesity.
Researchers published their findings in the journal Nature. In the study, the scientists replicated what farmers have been doing for decades to fatten up their livestock: feeding young mice a steady low dose of antibiotics, which in turn altered the composition of the bacteria in the gut. This also changed how the bacteria broke down nutrients. In some mice, the bacteria activated more genes that turned carbohydrates into short-chain fatty acids, as well as turning on genes related to lip conversion inside the liver.
These shifts in the molecular medium enable fat build-up. Just as farm animals gain weight when fed antibiotics, so did the mice. Martin Blaser, a microbiologist at the New York University in New York, states that parents might be doing the same to their children when they treat common ailments and ear infections with strong antibiotics. A disproportionate number of kids in the UK were overweight by the time they were 3 years old.
When antibiotics are given early in life, they come at a cost to parents, doctors, and patients. Microbes could also play a part to combat this but more work needs to be done before they can be used to fight obesity.
Reference: “Antibiotics in early life alter the murine colonic microbiome and adiposity” by Ilseung Cho, Shingo Yamanishi, Laura Cox, Barbara A. Methé, Jiri Zavadil, Kelvin Li, Zhan Gao, Douglas Mahana, Kartik Raju, Isabel Teitler, Huilin Li, Alexander V. Alekseyenko and Martin J. Blaser, 22 August 2012, Nature.