The prevalence of kidney stones in the United States has increased 70 percent since the 1970s, and a new report suggests that the use of oral antibiotics may be part of reason.

The study, in the Journal of the American Society of Nephrology, used health records of 13.8 million patients of general practitioners in Britain. The researchers had 25,981 people with kidney stones matched for sex and age with 259,797 controls. They tracked antibiotic exposure three to 12 months before the diagnosis.

After controlling for urinary tract infections, medications, diseases like gout and diabetes, and other variables, they found that exposure to any of five classes of antibiotics significantly increased the risk for kidney stones. The drugs ranged from broad-spectrum penicillins, which increased the risk by 27 percent, to sulfa drugs, which were associated with more than double the risk. Cephalosporins, fluoroquinolones and nitrofurantoin were also associated with increased risk. The risks for children under 18 were significantly higher than for adults.

The lead author, Dr. Gregory E. Tasian, a urologist at the Children’s Hospital of Philadelphia, said the mechanism is unclear, but that the most likely explanation is a complex interaction of the drugs with the urinary or gut microbiome.

In any case, he said, “We’re dealing with a risk-benefit relationship, and we want to make sure that antibiotics are prescribed without unnecessarily increasing adverse health outcomes.”