Mechanistic support from an ex vivo infant-gut model demonstrated that resistance-carrying plasmids can transfer between bacteria after antibiotic exposure, confirming the potential for horizontal gene transfer.

Functional pathway analyses showed that probiotic use was associated with decreased antibiotic resistance genes and resistance classes, especially to last-resort antibiotics like colistin, by week two.

Probiotic treatment, including Bifidobacterium, was shown to lower levels of drug-resistant pathogens such as Enterococcus, which are linked to infection risks and longer hospital stays.

Rapid colonization by probiotic Bifidobacterium was confirmed through sequencing, aiding microbiome maturation and reducing resistant pathogens.

Although short antibiotic courses did not significantly increase diversity, they were associated with early colonization by Klebsiella or Enterococcus and increased horizontal gene transfer, facilitating resistance gene spread.

Overall, the study underscores that probiotics can play a key role in reducing antimicrobial resistance and improving gut health in preterm infants, but further research is essential to optimize their use.

Probiotic-supplemented infants showed a gut microbiome dominated by beneficial bacteria like Bifidobacterium, with fewer early-life pathogens such as Klebsiella, Escherichia, Enterococcus, and Staphylococcus.

Infants who did not receive probiotics harbored more multidrug-resistant strains, including E. coli ST1193 and K. pneumoniae ST432, and carried higher plasmid burdens linked to horizontal gene transfer.

Probiotics help promote beneficial bacteria, reduce antibiotic resistance gene loads, and limit multidrug-resistant features, but they do not eliminate horizontal gene transfer risks, especially when antibiotics are used.

A recent study from the University of Birmingham highlights that administering probiotics alongside antibiotics to preterm infants with very low birth weight can reduce multidrug-resistant bacteria and foster a gut microbiome similar to that of full-term babies.

The research involved 34 preterm infants under 33 weeks' gestation, with some receiving probiotic treatment containing Bifidobacterium bifidum and Lactobacillus acidophilus, and others receiving short antibiotics, monitoring their gut bacteria during the first three weeks.

This study adds to the increasing use of probiotics in UK NICUs, supported by WHO guidelines, emphasizing their role in infection prevention and microbiome development.

While further research is needed to optimize probiotic strains, dosing, and duration, the findings suggest probiotics are crucial in antimicrobial stewardship and infection control in preterm infants.