A new study published in Nature Communications shows that preterm babies with very low birth weight who received a probiotic alongside antibiotics developed fewer multidrug-resistant bacteria and a more typical gut microbiome. The trial, involving 34 infants under 1500g (around 1–1.5% of babies globally), sequenced gut bacteria during the first three weeks after birth. Led by Professor Lindsay Hall and Dr. Raymond Kiu at the University of Birmingham the research found that probiotic treatment with a specific strain including Bifidobacterium helped establish bacterial communities more like those of full-term babies while also lowering levels of antibiotic resistance genes and reducing multidrug-resistant bacteria in the gut.

The study found that preterm babies given probiotics had lower levels of drug-resistant pathogens such as Enterococcus which are linked to infection risks and longer hospital stays, while also showing higher levels of beneficial gut bacteria. In contrast babies who did not receive probiotics developed gut microbiomes dominated by pathobionts capable of causing serious even life-threatening infections during early life and beyond regardless of antibiotic use. Professor Lindsay Hall of the University of Birmingham and the Quadram Institute Bioscience senior author of the study explained that while probiotics are already known to protect vulnerable preterm infants from severe infections, this research demonstrates that they also reduce antibiotic resistance genes and multidrug-resistant bacteria in the gut importantly doing so selectively, targeting harmful resistant strains without disrupting beneficial ones.

In the context of the global antimicrobial resistance crisis, these findings are highly significant, particularly for NICUs where preterm infants are most vulnerable. Probiotics are already in use across many neonatal units in the UK, with the WHO recommending their supplementation in preterm babies. This study highlights the benefits of such interventions, showing that probiotic Bifidobacterium rapidly establishes itself in the preterm gut within the first three weeks of life, promoting microbiota maturation while reducing multidrug-resistant pathogens. According to Dr. Raymond Kiu, first and co-corresponding author from the University of Birmingham, sequencing technology confirmed this successful colonization and revealed how probiotics can offset harmful pathogens, while also offering new insights into the interplay between antibiotics, probiotics, and horizontal gene transfer in shaping the early-life microbiome.

Source: https://www.birmingham.ac.uk/news/2025/probiotics-for-preterm-babies-lowered-antibiotic-resistant-bacteria-in-gut