Repeated use of some types of antibiotic may raise the risk of developing type 2 diabetes , warn researchers . Findings from a new US study underline the need to reduce unnecessary antibiotic prescriptions , it is claimed . More than 3 million Britons are diagnosed with diabetes and nine out of ten have type 2 which occurs when the body gradually loses the ability to process blood sugar . Researchers looked at the number of antibiotic prescriptions given to 200,000 diabetics a year before they were diagnosed , and found those given at least two courses had a higher chance of getting the condition . Type 2 is strongly linked to lifestyle factors such as being overweight or obese , leading a sedentary lifestyle and eating an unhealthy diet . Researchers from the Departments of Gastroenterology and Medical Oncology at the University of Pennsylvania carried out the investigation . They looked at the number of antibiotic prescriptions given to more than 200,000 diabetics in the UK at least one year before they were diagnosed with the disease , and compared this to the number given to 800,000 non-diabetic patients of the same age and sex . They found that patients prescribed at least two courses of penicillins , cephalosporines , quinolones and macrolides were at higher risk of being diagnosed with type 2 diabetes . The risk increased with the number of antibiotic courses prescribed , says a report in the European Journal of Endocrinology ( must credit ) . More than 3million Britons have diabetes and nine out of ten have type 2 which occurs when the body loses the ability to process blood sugar . Patients prescribed 2-5 courses of penicillins – used for a variety of infections - increased their risk of diabetes by 8 per cent . The risk increased by 23 per cent for those having more than five courses of penicillins . Patients having 2-5 courses of quinolones , used in respiratory and urinary tract infections , had an increased diabetes risk of 15 per cent , which rose 37 per cent for those having more than five courses . The risk was calculated after adjusting for other risk factors such as obesity , smoking history , heart disease and history of infections . Study leader Dr Ben Boursi said ‘ 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. ’ senior author Dr Yu-Xiao Yang added : ‘ 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. ’ There was no increase in risk associated with use of antivirals or anti-fungal medications and the study found little evidence of a link between antibiotic use and the risk of type 1 diabetes . Dr Boursi said ‘ Over-prescription of antibiotics is already a problem around the world as bacteria become increasingly resistant to their effects . ‘ 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. ’ Prof Jodi Lindsay , Professor of Microbial Pathogenesis , St George ’ s , University of London , said ‘ Patients with type 2 diabetes have an increased risk of developing infections , and therefore they are more likely to be prescribed antibiotics to treat those infections . ‘ In the year prior to diabetes diagnosis , patients may show some signs of disease and may also have a higher risk of infection , and therefore receive more antibiotics . ‘ This is a very large and helpful study linking diabetes with antibiotic consumption in the UK public , but at this stage we don ’ t know which is the chicken and which is the egg . ‘ The idea that antibiotics might contribute to diabetes development might be important and more research needs to be done . ’
doctors administered antibiotic prescriptions to treat diabetes sufferers . Found those given two or more medications were more likely to be diabetic . 50 million Britons are diabetic , and 95 per cent suffer from Type diabetes .