Overuse of Antibiotics May Cause Long-Term Harm

Aug. 25, 2011— -- While antibiotics have certainly benefited many in myriad ways, an overuse of antibiotics may be changing our entire bacterial makeup, says Dr. Martin Blaser, chairman of the department of medicine at New York University Langone Medical Center.

In his opinion piece published in the journal Nature, Blaser implores doctors to be more prudent in prescribing antibiotics because of these potential changes, and because overprescribing can cause antibiotic resistance, which has received much attention in recent years.

"Antibiotics are miraculous," Blaser told ABC News. "They've changed health and medicine over the last 70 years. But when doctors prescribe antibiotics, it is based on the belief that there are no long-term effects. We've seen evidence that suggests antibiotics may permanently change the beneficial bacteria that we're carrying."

In the editorial, Blaser hypothesized that the overuse of antibiotics may even be fueling the "dramatic increase" in many illnesses, including type 1 diabetes, allergies and inflammatory bowel disease by destroying the body's friendly flora, or protective bacteria.

"We need to cut down on excess use," said Blaser. "Over time, the scientific community has to create a more narrow spectrum of antibiotics to kill specific organisms and not all bacteria, but we don't have those yet."

Dr. Cesar Arias, assistant professor of infectious disease at University of Texas Medical School, wholeheartedly agreed with the editorial.

"We use these without much care and without really thinking," said Arias. "People go to the doctor for a sore throat, which is usually viral, and they're get antibiotics."

"These drugs affect what we're colonized with, particularly the digestive tract," said Arias. "If you alter your flora, you can promote certain superbugs to colonize in your gut and get into the bloodstream."

The average American child will receive 10 to 20 courses of antibiotics by the time he is 18 years old, and one-third to one-half of pregnant women will receive them during pregnancy, according to Blaser's report.

But it is not always easy for doctors to cut back on prescribing antibiotics if a patient wants it.