Repeated use of some antibiotics could increase a person’s risk of developing type 2 diabetes, according to research published online Tuesday in the European Journal of Endocrinology.
In the study, scientists from the University of Pennsylvania found that men and women who had ever been prescribed with at least two courses of specific types of antibiotics were more likely to eventually be diagnosed with type 2 diabetes than those who had taken no more than one.
The antibiotics used in the research came from one of four categories, according to LiveScience: penicillins, cephalosporins, quinolones and macrolides. The authors reviewed a database of UK patients, looking at the number of antibiotic prescriptions given to over 200,000 diabetic patients at least one year before those individuals were diagnosed with the condition.
They then compared those figures with the number of antibiotics prescribed for roughly 800,000 men and women who did not have diabetes, but were the same average age as the patients in the other group. They found that the more courses of antibiotics that were prescribed to a person, the greater the risk that he or she would go on to develop the disease.
Patients who had been prescribed between two and five courses of penicillin increased their risk of diabetes, according to the Daily Mail, and the risk increased by 23 percent for those receiving more than five courses of the frequently used antibiotic versus the one- or no-course group.
Those who were given between two and five courses of quinolones, which are used to treat respiratory and urinary tract infections, had an increased diabetes risk of 15 percent, and those receiving more than five courses saw that risk shoot up by 37 percent. The risk remained even when other factors, including obesity and heart disease, were accounted for.
Those who were given just one course of antibiotics showed no such increase in diabetes risk, the researchers reported. Nor was there any link found between exposure to anti-virals and anti-fungals and diabetes risk. The reason for the association between frequent antibiotic use and the risk of diabetes is not unclear, but may be related to a gut bacteria imbalance, they wrote.
“While our study does not show cause and effect, we think changing levels and diversity of gut bacteria could explain the link between antibiotics and diabetes risk,” co-author Dr. Yu-Xiao Yang, an assistant professor of medicine and epidemiology at the University of Pennsylvania in Philadelphia, explained in a statement, according to LiveScience.
“Gut bacteria have been suggested to influence the mechanisms behind obesity, insulin resistance and diabetes in both animal and human models. Previous studies have shown that antibiotics can alter the digestive ecosystem,” added lead author Dr. Ben Boursi.
“Over-prescription of antibiotics is already a problem around the world as bacteria become increasingly resistant to their effects,” he continued. “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.”