Antibiotics affect babies' gut microbes after birth

Experts say clinicians should consider using antibiotics in a way that is least harmful to the newborn's microbiome, the microbes that live in our bodies

Under current guidelines, antibiotics that target a broad range of bacteria -- known as broad-spectrum antibiotics -- are currently prescribed in 4 to 10 percent of newborns with suspected infection

However, experts say prescribing antibiotics is unnecessary in most cases because only a small percentage of people who take antibiotics end up being diagnosed with an infection

This overmedication is to ensure that those who are eventually found to have the infection get early treatment, as any delay could quickly be life-threatening

Researchers from the Universities of Edinburgh and Birmingham, and the Spartan Hospital and University Medical Centre Utrecht in the Netherlands conducted a clinical trial involving 227 infants to analyse how antibiotics affect the newborn's microbiome

About 147 infants with suspected sepsis received one of three standard antibiotic treatments

All infants had rectal or stool samples before and after treatment, and at 1, 4, and 12 months

The study found that newborns who received antibiotics had significantly lower levels of different types of bifidobacteria compared with babies who did not receive antibiotics

These microbes aid in the digestion of human breast milk and promote gut health, while also supporting the immune system to fight infection

The team also found an increase in the number and abundance of potentially disease-causing bacteria, as well as genes associated with antimicrobial resistance, in people treated with antibiotics

Of the 695 different bacteria, 251 were observed to change after treatment, altering the balance between good and bad bacteria in favor of more potentially harmful bacteria

Despite gradual recovery over time, changes in the microbiome and antimicrobial resistance genes persisted for at least 12 months, and did not improve with breastfeeding, which is known to help infants' immune systems

Professor Debby Bogaert, Chair of Paediatric Medicine at the University of Edinburgh and head of the study, said: "We were surprised by the magnitude and duration of the effect of broad-spectrum antibiotics on the infant microbiome, compared to the effect of the same antibiotics on the adult microbiome

Of the three antibiotic regimens tested, the combination of penicillin and gentamicin was found to have the least deleterious effect on the infant gut microbiota and the number of antimicrobial resistance genes that emerged

The researchers concluded that this particular combination of antibiotics is best used in the treatment of suspected infections in newborns

Dr Marlies van Houten, a general paediatrician at Spane Hospital in the Netherlands and co-principal investigator of the study, said, "The fact that the initiation, rather than the duration, of antibiotic treatment appears to be responsible for the damage to the microbiome underscores the need for better biomarkers, or biological predictors, to more accurately determine which infants will develop an infection and therefore require antibiotics, and which will not

Professor William van Schack, Professor of Microbiology and Infectious Diseases at the University of Birmingham, said: "It is particularly disturbing that we have observed a large increase in Klebsiella and Enterococcus numbers following antibiotic treatment of newborns, both of which These bacteria are important multidrug-resistant pathogens
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"This underscores the importance of further research balancing the need and effectiveness of these antibiotics with the risk of developing genes associated with resistance
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The development of new interventions, such as live biotherapeutics - an approach produced by living cells or involving There may also be room for therapeutic approaches with living cells, which effectively restore the composition of the gut microbiota in infants after antibiotic treatment
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The findings were published in the journal Nature Communications
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This work was funded by the Netherlands Organization for Health Research and Development
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Journal Reference :

1. Marta Reyman, Marlies A.
   van Houten, Rebecca L.
   Watson, Mei Ling JN Chu, Kayleigh Arp, Wouter J.
   de Waal, Irene Schiering, Frans B.
   Plötz, Rob JL Willems, Willem van Schaik, Elisabeth AM Sanders, Debby Bogaert.
   Effects of early-life antibiotics on the developing infant gut microbiome and resistome: a randomized trial .
   Nature Communications , 2022; 13 (1) DOI: 10.
   1038/s41467-022-28525-z