We know that antibiotics can cause significant problems. Misuse of antibiotics can bring on antibiotic resistance in the bacteria themselves, which can make dangerous infections even harder to overcome.

Antibiotics also can cause serious health issues in the people who take them. This is because antibiotics damage cells of any kind, not only the bacteria they’re targeting.

Kidney damage and hearing loss have been reported in people taking antibiotics for long periods of time. Fortunately, thanks to a new study, we now have some pretty good clues as to what’s actually going on in our cells in the presence of antibiotics that leads to the frequent health problems that arise. There are also some promising solutions.

Antibiotics can damage the host’s cell machinery as well as the bacteria infecting it. This is definitely not the desired effect, but it could explain the health problems long-term antibiotic use can bring on.

The new study built upon previous research suggesting that antibiotics can produce reactive oxygen species (ROS), which damage DNA. The idea, of course, is to damage the bacteria’s DNA, but along the way the antibiotics can damage the host’s cell machinery as well. This is definitely not the desired effect, but it could explain the health problems long-term antibiotic use can cause.

The researchers, a team at Harvard, Wake Forest, and Boston Universities, observed the effects of three different kinds of antibiotics – quinolones, beta-lactams, and aminoglycosides – in human cells cultured in the lab. Specifically, they found that the antibiotics upset the electron transport chain, causing a buildup of ROS, and in turn, damage to the cells’ DNA, proteins, and membrane lipids (fats). Live mice who were administered the antibiotics showed similar changes in their cellular machinery.

What was especially interesting was that the team found that administering strong antioxidants to the mice at the same time reversed the cell damage caused by the antibiotics, but didn’t undermine the effectiveness of the antibiotic. Also important was the fact that the antibiotic tetracycline, part of the class known as bacteriostatics, which impedes bacterial growth without actually killing them, did not have the same damaging effects that the others had.

The results are encouraging, said the authors, since they suggest that it might be a good idea for doctors to prescribe powerful antioxidants along with antibiotics – or to prescribe bacteriostatic antibiotics more often.

The overuse of antibiotics in anyone, particularly kids, has been the subject of much debate and criticism in the last decade. Recently, antibiotic use in kids has been linked to obesity, possibly because of the imbalance it can cause in gut bacteria – though the exact mechanism is not yet clear.

Other evidence has suggested that reducing antibiotic use does not necessarily harm one's health, since infections do go away without them. And the excessive routine use of antibiotics in animals used for food (for example, chickens and cows) has, of course, also been an enormous concern in recent years.

The current study's findings provide some good evidence as to what’s happening in our cells when we take antibiotics, and suggests a few effective methods to help address the issue, which is fast becoming a global health problem.

The study is published in the journal Science.