New research suggests that doctors should be cautious about giving newborns antibiotics because they can upset a baby's gut microbiome -- the balance of bacteria in their digestive systems.
"We were surprised with the magnitude and duration of the effects of broad spectrum antibiotics on the infants' microbiome when compared to effects of those same antibiotics on adults' microbiota," said study leader Dr. Debby Bogaert, chair of pediatric medicine at the University of Edinburgh in Scotland.
"This is likely because the antibiotic treatment is given at a time that infants have just received their first microbes from their mother and have not yet developed a resilient microbiome," Bogaert said in a university news release.
Broad-spectrum antibiotics are prescribed to between 4% and 10% of newborns for suspected infections, the study noted. In most cases, they are unnecessary because the babies don't actually have an infection.
Along with the risk of antibiotic resistance, overuse of antibiotics in newborns results in a decrease in bacteria that promote good health, the researchers said.
To find out how antibiotics affect digestive system bacteria in newborns, the researchers compared 147 infants who received one of three standard antibiotic treatments for suspected sepsis, and 80 babies who weren't prescribed antibiotics.
Stool samples were collected before and after antibiotic treatment, and at 1 month, 4 months and 12 months of age. Babies who were prescribed antibiotics had a significant increase in levels of Bifidobacterium species compared with babies who weren't given antibiotics.
These species aid digestion of human breast milk, promote gut health and support the immune defense against infection.
Newborns who received antibiotics also had an increase in potentially disease-causing bacteria and in the number and abundance of genes related to antibiotic resistance, the study found.
Infants who were given antibiotics had a change in 251 of nearly 700 different bacteria assessed, which tilted the balance to potentially more harmful types.
The changes persisted for at least 12 months and did not improve with breastfeeding, which is known to help a baby's immune system, according to the findings.
The study was published Feb. 16 in the journal Nature Communications.
"The fact that start of antibiotic treatment rather than duration seems to be responsible for the damage to the microbiome underlines we need better biomarkers or biological predictors to more accurately determine which infant will develop an infection and thus require antibiotics, and which will not," said study co-author Dr. Marlies van Houten, a pediatrician at Spaarne Hospital in the Netherlands.
For more on antibiotics, see the American Academy of Pediatrics.
SOURCE: University of Edinburgh, news release, Feb. 18, 2022