The Microbiome: Linking Bacteria, Health, and Disease

Robert C. Rickert, PhD; Scott Peterson, PhD


June 19, 2013

Editorial Collaboration

Medscape &

In This Article

Do Antibiotics Influence Obesity?

Dr. Peterson: Another study that we're involved in with scientists at New York University involves the study of obesity and the relationship with the gut microbiome.[1] This was prompted by a collaborator's understanding or recognition of the fact that in the agricultural industry, for more than 50 years now, they've been feeding livestock low doses of antibiotics. That had the effect of increasing their body mass.

This was an agricultural trick that has obvious economic utility, but he got to wondering whether that could be used to establish a model of obesity in mice. So he developed a mouse model in which they fed mice low doses of antibiotics from a young age. Sure enough, they developed an increased fat percentage in their body. Their weight actually doesn't increase as a result of the antibiotics, nor does their lean body mass, but their fat content and the percentage of fat in their body increases.

Dr. Rickert: So the mice are getting obese?

Dr. Peterson: Essentially, they're getting obese, and it's through this connection of altering and influencing the microbiome, through that low dose of antibiotics. It's not wiping it out, but just altering it enough that it's affecting the metabolism within the gut as a result of the change in the bacterial population. That affects the human host in the form of obesity.

This is a fascinating study. We're learning a lot about things that have previously not been recognized from the host perspective -- it is much better understood what happens in the obese individual compared with the lean individual. But connecting it now to the microbiome as a major influence of obesity is a new thing. We really are pleased with our initial findings with this antibiotic-treated mouse model.