The more we learn about type 2 diabetes, the more we appreciate that there are many, many factors that play into the development of this complex medical condition.  The bugs that live in our intestines (called microbiota) are falling under increased scrutiny in how they affect our metabolism.  A new study suggests that antibiotic use (which changes our microbiota) increases the risk of type 2 diabetes.
The study, conducted by Mikkelsen and colleagues and published in the Journal of Clinical Endocrinology & Metabolism (a journal that we endocrinologists love to geek out over) looked at 12 years of data from the entire population of Denmark.  They found that those who had filled 2-4 prescriptions for antibiotics has a 21% higher risk of having type 2 diabetes, compared with those who had filled 0-1 antibiotic prescriptions.  The higher the frequency of antibiotic usage, the higher the risk of having type 2 diabetes. The higher use of antibiotics in type 2 diabetes patients was seen for up to 15 years before the diagnosis of type 2 diabetes, as well as after the diagnosis of diabetes.  
So does this clearly tell us that antibiotics destroy our gut bacteria and cause diabetes?  No.  The data could also be interpreted to reflect that diabetics (diagnosed or not yet diagnosed) are at
higher risk of infection, therefore more likely to need antibiotics.  That being said, the fact that the association between antibiotic use and diabetes was seen for up to 15 years before diabetes was diagnosed, makes it unlikely that these data simply reflect diabetics needing treatment for infections. (while diabetes has often been present 5-7 years before diagnosis, 15 years of undetected diabetes is unlikely). 
We are still in the early stages of understanding how our gut bugs affect our metabolism, but there is increasing evidence that they play an important role not only in the development of obesity, but also potentially in the development of type 2 diabetes. I will be watching this area with interest!

Follow me on twitter! @drsuepedersen © 2015