Newborns given antibiotics at greater risk of later illnesses
Published 01/01/2013 | 05:00
NEWBORN babies treated with antibiotics have an increased risk of developing asthma, allergies and becoming obese in later life, according to a new study by Irish scientists.
The joint study by Cork University Maternity Hospital (CUMH), Teagasc and the Hospital for Sick Children in Toronto compared the bacterial composition in the gut of nine infants who were given antibiotics within 48 hours of birth with those of nine babies who received no antibiotics.
Researchers discovered that, two months later, those babies who were treated with antibiotics had significant numbers of potentially disease-causing bacteria.
Dr Catherine Stanton, a scientist with the Alimentary Pharmabiotic Centre at the Teagasc Food Research Centre in Fermoy, Co Cork, said the findings had implications for how antibiotics were given to very young babies.
"This research suggests that the merits of administering broad spectrum antibiotics – those that kill many bacterial species – in infants should be reassessed to examine the potential to use more targeted, narrow-spectrum antibiotics, for the shortest period possible," she warned.
"By altering the gut microbia, and thus the immune system very early in life, the antibiotics could negatively influence long-term health, particularly by increasing the risk of developing asthma, allergy and obesity."
The study found that four weeks after the infants were given the antibiotics, the number of beneficial bacteria in the gut was significantly reduced. After eight weeks the diversity of bacteria in the gut was still diminished and bacteria with the potential to cause disease were now dominant.
However, Dr Tony Ryan, consultant neonatologist at CUMH and a co-author of the study, stressed that antibiotics are rarely given to newborns and are immediately stopped when no longer needed.
The two antibiotics looked at by researchers – ampicillin and gentamicin – are only given to newborns in rare circumstances, for example in the treatment of Group B streptoccocal infections.
"We have about 9,000 babies born in Cork University Hospital each year and some studies show that up to one-quarter of mums are colonised (by Group B strep) and half of them will have babies who will be colonised, that's around 1,000 babies. Only between 10 and 30 babies a year might develop Group B strep septicemia," he explained.
Dr Ryan said babies who are born with breathing problems or with unstable temperatures undergo blood culture tests.
While doctors await the results of those blood tests, the newborns are immediately started on antibiotics.
If the blood culture comes back negative, antibiotic treatment is stopped.
"The antibiotics we use in the newborn period are used in babies with symptoms and only in the short term while infections are there," he stressed.
The researchers used advanced DNA sequencing to identify the species of bacteria in the gut and to quantify their numbers.