The Helsinki University study compared two antibiotics administered to children in Europe and Finland – penicillin and macrolides and found that the latter caused more significant changes to intestinal bacteria.
This was especially the case for children who had used wide-spectrum macrolide antibiotics such as azithromycin or clarithromycin.
"It takes more than a year for intestinal microbiota to recover from a course of antibiotics. If a child has repeated antibiotics treatments in its first year of life, the microflora may not necessarily fully recover," said Helsinki University researcher Katri Korpela.
Researchers are not quite sure why macrolides are more lethal for intestinal bacteria than penicillin. One possible explanation apart from macrolides’ broad spectrum impact could be that penicillin doesn’t end up in the bowel.
"One difference is that macrolides separate into the stool, while penicillin ends up in urine," Korpela explained.
Links to obesity and asthma
It has previously been held that the use of antibiotics in early childhood is linked to an increased risk of succumbing to immune-mediated diseases such as irritable bowel syndrome, asthma and obesity.
The new research shows that the during the first two years of life children who had received several macrolide antibiotic treatments and the amount of medication used had a clear link to a higher body mass index.
Heavy use of macrolides in the first two years was also connected to increased risk of asthma. Macrolides also led to the development of antibiotic resistance.
"Penicillin-type antibiotics were clearly shown to have a lower impact than macrolides on the composition of intestinal bacteria and their behaviour," Korpela said.
Antibiotics used too freely in Finland
According to Korpela Finland prescribes too many broad spectrum antibiotics compared to other European countries. Because macrolides have more known side effects than penicillin, the researchers recommended avoiding the use of macrolides as a primary antibiotic.
"In Finland we use too much of these [macrolides]. It is used far less in other Nordic countries and the Netherlands."
According to the research team the use of antibiotics should in any case be limited only to real need.
"Antibiotics should not be used to treat self-limiting infections and never just to be on the safe side," they advised, referring to infections that spontaneously clear up without specific treatment.
The research was led by Professor Willem de Vos and involved 142 children aged 2 – 7 years old. The research was published in the scientific journal Nature Communications (siirryt toiseen palveluun).
