Doctors often prescribe antibiotics freely, thinking that they harm bacteria while leaving human tissue unscathed. A studied published in July 2013 suggests this is not the case.
The research study
has found that certain antibiotics, when used over a prolonged period of time, can trigger a phenomenon called oxidative stress
. This effect is a condition in which human cells can be programmed into producing chemically reactive oxygen molecules. For the killing of the desired microorganism this is effective; however the damage caused to the DNA, enzymes and cell membranes of the bacteria can also affect the body’s own cells.
As well as killing bacteria, the oxidizing process can negatively affect parts of body cells called mitochondria
. These function to supply human cells with energy. This was seen with three common antibiotics: ciprofloxacin, ampicillin and kanamycin. Oxidative stress reflects an imbalance between reactive oxygen in the body and the body’s ability to readily detoxify the by-products or to repair the resulting damage.
The concern was shown in studies on mice, where use of the three antibiotics led to signs that the lipids (fats) in the mice became damaged as well as leading to levels of glutathione, one of the body's natural antioxidants, to fall.
Commenting on the findings, Dr. Don Ingber, head of the institute which led the study, is quoted by the Alternative Daily
as saying: "Doctors have known for years that antibiotics occasionally cause serious side effects and Jim's new findings offer not one but two exciting new strategies that could address this long-neglected public health problem."
The researchers behind the study have speculated whether an antioxidant, such as N-acetylcysteine, could be used to reduce the impact of the antibiotic. However, this raises concerns about people consuming a potentially harmful chemical.
The research was carried out by the Wyss Institute for Biologically Inspired Engineering at Harvard University under a team led by Dr. Jim Collins.