Common antibiotics do not increase the risk of type 1 diabetes or celiac disease among children who have a genetic susceptibility for developing those diseases, multinational researchers, including those from the University of Florida, have found.

The TEDDY Study Group, which includes University of Florida researcher Eric Triplett, PhD, found that everyday antibiotics are not associated with a greater risk of autoimmunity for either disease.

The group’s findings were published in JAMA Pediatrics journal.

Triplett said it is important to learn how antibiotics might influence Type 1 diabetes and celiac disease because the medications have been suggested as a cause for the increasing incidence of autoimmune diseases in industrialized nations. Previous human studies have showed conflicting results for an association between antibiotic use and Type 1 diabetes, an autoimmune disease that results in destruction of cells in the pancreas that make insulin. In celiac disease, eating gluten triggers an immune response that attacks the small intestine.

“I thought we should get to the heart of the matter because you want parents to know whether their children are going to be put at risk when a physician prescribes an antibiotic,” said Triplett, a professor and chair of the department of microbiology and cell science at the UF Institute of Food and Agricultural Sciences and a member of the UF Diabetes Institute, part of UF Health.

The study analyzed 8,495 children in the United States, Finland, Sweden and Germany who were genetically at risk for Type 1 diabetes, as well as 6,558 children who had a genetic risk for celiac disease. Parents reported when their children took the most common antibiotics — including penicillin, amoxicillin and cephalosporin — between the ages of 3 months and 4 years.

The children in the study were prescribed antibiotics more than 38,000 times before the age of 4, with amoxicillin being the single most commonly used compound. Middle-ear infections were the most common reason for using antibiotics, accounting for 62 percent of all uses. Macrolide and beta-lactam antibiotics, which include erythromycin and penicillin derivatives, accounted for 70.5 percent of all antibiotics used by children in the study.

The researchers found that 5.5 percent of the high-risk children in the study developed antibodies for Type 1 diabetes and 11.6 percent of them had celiac disease autoimmunity before the age of 4. However, exposure to antibiotics was not associated with the development of antibodies, the researchers concluded. The findings are from one of just two studies that have reviewed antibiotic use in young children, with the other being limited to effects on week-old infants, researchers said.

“We have no evidence that pediatric use of antibiotics affects the risk of Type 1 diabetes or celiac disease in either direction. It doesn’t increase or decrease the risk,” said Kaisa M. Kemppainen, PhD, a co-author of the study and a postdoctoral associate in the department of microbiology and cell science at the UF Institute of Food and Agricultural Sciences.

Triplett said the message for parents and physicians is clear and convincing.

“Don’t worry about the standard antibiotics for children under age 4. If you’re concerned and there is a history of Type 1 diabetes or celiac disease in your family, antibiotics are not going to contribute to the risk of developing the disease,” he said.

The research was conducted as part of The Environmental Determinants of Diabetes in the Young study, also known as the TEDDY study, which is funded by the National Institutes of Health’s National Institute of Diabetes and Digestive and Kidney Diseases. TEDDY is a multicenter, multinational investigation designed to identify whether environmental factors such as infections, diet, stress or other conditions trigger the onset of Type 1 diabetes in genetical