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.

Overuse of Antibiotics May Cause Long-Term Harm

"Physicians are often placed in unpleasant situations when patients demand antibiotics for themselves or their children, even when it is not in their best interests," said Dr. Philip Cunningham, associate professor of biological sciences at Wayne State University in Detroit. "Patients must understand the reasons when antibiotics are not prescribed."

Whether or not people can overcome resistance and change is not widely known yet.

Prevention is the key," said Dr. Richard Colgan, associate professor of family and community medicine at the University of Maryland School of Medicine. "The best way to avoid antimicrobial resistance is to be judicious in using antibiotics. That is not to mean that if your doctor recommends [antibiotics] you should discard this advice."

While part of the answer is to reduce antibiotic intake when possible, Blaser said he speculates and fears that humans have already lost some "ancestral organisms" that help protect us.

"I think we'll soon be inoculating babies with these lost bacteria," said Blaser. "Antibacterials are everywhere. We might be harming ourselves out of a lot of benefit."