Repeated use of certain types of antibiotics may put people at increased risk of developing Type 2 diabetes, possibly by changing their gut bacteria, according to new research published in the European Journal of Endocrinology. An estimated 29 million people in the United States have Type 2 diabetes, and another 86 million people have prediabetes, putting them at increased risk of developing the condition.
The bacterial composition of the gut is known to influence various biological processes related to the development of diabetes. Previous research has indicated that antibiotics, which are commonly used in western countries, can alter the bacterial makeup of the digestive system.
To determine whether past antibiotic use increases diabetes risk, researchers from the University of Pennsylvania looked at the number of antibiotic prescriptions given to 200,000 people with diabetes in the United Kingdom, compared to the number of antibiotic prescriptions given to 800,000 people without diabetes of the same age and sex.
The researchers found that those who had been prescribed at least two courses of penicillins, cephalosporines, quinolones, or macrolides were at higher risk of developing Type 2 diabetes, with the risk increasing alongside the number of courses of antibiotics prescribed. For instance, people who had been prescribed two to five courses of penicillins had an 8% increase in Type 2 risk, while those prescribed more than five courses had a 23% increase in risk. Those who were prescribed two to five courses of quinolones had a 15% increase in Type 2 diabetes risk, while those who were prescribed more than five courses had a 37% increase in risk. These risks were calculated after adjusting for other factors for Type 2, including obesity, heart disease, and smoking.
Antiviral and antifungal medicines were not found to be associated with increased diabetes risk, and little evidence was found linking the use of antibiotics to the development of Type 1 diabetes.
“Gut bacteria have been suggested to influence the mechanisms behind obesity, insulin resistance, and diabetes in both human and animal models,” stated lead study author Ben Boursi, MD. “Our findings are important, not only for understanding how diabetes may develop, but as a warning to reduce unnecessary antibiotic treatments that might do more harm than good.”
Although the study was observational and therefore does not show cause and effect, the researchers believe that changing levels and diversity of gut bacteria could explain the link between antibiotics and diabetes risk.
For more information, see the article, “Repeated use of antibiotics linked to diabetes risk,” or see the study’s abstract in the European Journal of Endocrinology. And to learn more about other possible origins of Type 2 diabetes, see the piece “Type 2 Diabetes: Are We Closer to Knowing ‘Why?'”