Denpa News Camille Goemans, a microbiologist, has studied various antidotes that can minimize the harmful effects of antibiotics. Thanks to her work at the European Laboratory of Molecular Biology (EMBL) in Germany, where she is conducting a postdoctoral study, she has been able to identify several promising molecules. “Anti-dotes” are already contained in medicines used in medicine.
144 studied antibiotics
“The most common side effects of antibiotics are gastrointestinal problems and recurrent Clostridoides difficile infections. In the longer term, allergic, metabolic, immunological, and inflammatory diseases can also develop,” said the scientist. In the study she conducted at the EMBL, in the group of Dr. Nassos Typas, in collaboration with Dr. Lisa Maier from the University of Tübingen, Camille Goemans has analyzed the effects of 144 antibiotics on the well-being of the most abundant bacteria in our gut microbiota. This will improve our understanding of the harmful effects of antibiotics on gut flora and thus propose new strategies to reduce them.
Tetracyclines and macrolides: a deadly duo for the microbiota
Using cell cultures, laboratory mice, and human microbiota samples, the researchers showed that tetracyclines and macrolides not only inhibit the growth of microbiota bacteria but also kill them. “Half of the tested bacterial strains do not survive treatment with these antibiotics,” explains the EMBL.
“We did not expect this effect. Previously, these classes of antibiotics were assumed to only stop the growth of bacteria, but not kill them. The experiments show that this assumption does not hold for about half of the gut microbes we studied. Doxycycline, erythromycin, and azithromycin, for example, three commonly used antibiotics, killed several common types of gut bacteria, while only inhibiting the growth of others,” explains Camille Goemans.
To limit this collateral damage, the team examined the current pharmacopeia. The idea was to find a second drug that could suppress the harmful effects of antibiotics on the beneficial bacteria of the gut microbiota while maintaining the desired effect of the antibiotic on the pathogenic bacteria. Some 1,200 drugs were considered. A dozen of these seem to offer some protection to the bacteria of the gut microbiota.
Our approach, which combines an antibiotic with an antidote, could lead to new therapeutic options to reduce the side effects of antibiotics on our gut flora,” says Camille Goemans.
“But beware,” she adds immediately, “we are not here in a clinical trial. Our work is basic research. These drugs, which may eventually play a role as antidotes, are molecules of different classes. They are administered under different types of pathologies and have side effects of their own.
“The most potent antidotes were the anticoagulant drug dicumarol, the gout drug benzbromarone, and two nonsteroidal anti-inflammatory drugs, tolfenamic acid, and diflunisal.”
“No antidote will protect all the bacteria in our gut, but this concept opens the door to developing personalized strategies to keep our microbiota healthy,” she says. “This could ultimately reduce the occurrence of diseases related to an imbalance in the gut flora.”