13 October (NWN) — Tetracyclines and macrolides, two commonly used classes of antibiotics, stop beneficial gut bacteria from growing and eventually kill them, found a study published Wednesday by Nature.
The data showed that in an analysis of the effects of 144 repeatedly prescribed antibiotics on the gut microbiome, a collection of helpful bacteria that aid in digestion and boost immunity, nearly half of the strains tested survived treatment with these antibiotics. were not left.
Although these drugs are important in the treatment of bacterial infections and save millions of lives, they undermine one of the body’s first lines of defense against pathogens and compromise the microbiota’s many beneficial effects on health, The researchers said.
Common side effects of what researchers call “collateral damage” due to antibiotics are gastrointestinal problems and recurrent Clostridoides difficile, or C. Diffs are infections.
According to the researchers, the drugs also contribute to long-term health problems, such as the development of allergic, metabolic, immunological or inflammatory diseases.
“Many antibiotics inhibit the growth of various pathogenic bacteria,” study co-author Lisa Meier said in a press release.
“This broad activity spectrum is useful when treating infections, but it increases the risk that microbes in our gut are also targeted,” said Meier, a researcher at the University of Tübingen in Germany.
According to the Harvard T.H. Chan School of Public Health, the gut microbiome is made up of many different microbial species and viruses that enable the body to use nutrients more efficiently and prevent harmful bacteria from settling in our gut. .
When bacterial infections are treated with antibiotics, however, there is a risk of damage to the gut microbiome, leading to an imbalance in our microbiota composition, commonly referred to as dysbiosis, Maier and colleagues said.
Diarrhea is a common short-term effect of dysbiosis, while allergic conditions such as asthma or food allergies and obesity are potential long-term consequences.
The fact that antibiotics are also active against gut microbes has been known for a long time, but their effects on the large diversity of microbes in the gut are unclear, according to the researchers.
For this study, Maier and colleagues evaluated how 144 commonly prescribed antibiotics affected the growth and survival of 27 bacterial strains found in the gut microbiome.
The researchers determined the concentrations at which an antibiotic would affect these bacterial strains for more than 800 antibiotic-strain combinations.
The researchers said that the tetracyclines and macrolides selectively killed specific gut microbes, meaning that their use could cause these microbes to be inadvertently lost from the gut microbiota much faster than the microbes for which growth only inhibited, the researchers said.
This could explain the strong microbiota shift that some patients being treated with these antibiotics experience, he said.
“We did not expect to see this effect with tetracyclines and macrolides,” study co-author Camille Gomens said in a press release.
“Doxycycline, erythromycin and azithromycin, three commonly used antibiotics, kill many abundant gut microbial species,” said Gomens, a postdoctoral fellow at the University of Tübingen.
However, there may be a way to reduce the damage, as researchers combined the antibiotics erythromycin or doxycycline with a set of about 1,200 pharmaceuticals to identify drugs that can protect two abundant bacterial species from these antibiotics. Can save
In doing so, they identified several non-antibiotic drugs that could protect these gut microbes and other related species, the researchers said.
And combining one antibiotic with a protective second drug did not compromise the former’s effectiveness against harmful bacteria.
“Our approach that combines antibiotics with a protective antidote could open up new opportunities to reduce the harmful side effects of antibiotics on our gut microbiome,” Maier said.
“No single antidote will be able to protect all the bacteria in our gut, especially since they vary greatly among individuals, but this concept opens the door to developing new personalized strategies for keeping our gut microbes healthy.” ,” He said.