Special lactic acids reduce antibiotic resistance in infants
Researchers from The Technical University of Denmark, DTU, document that a special subgroup of naturally occurring bifidobacteria plays a crucial role in reducing antibiotic resistance in infants.
Special lactic acids produced by bifidobacteria, which proliferate in the intestines of infants when they are breastfed, play a key role in keeping antibiotic-resistant bacteria at bay, according to new research from DTU. Photo: Colourbox
Monday 15 September 2025
Peter Aagaard Brixen
Infants with high levels of antibiotic-resistant bacteria face a greater risk to their health if they need to be treated with antibiotics when they contract infectious diseases during their first year of life. Now, researchers at DTU have discovered a way to combat antibiotic-resistant bacteria by nourishing a special subgroup of bifidobacteria that is naturally occurring in the gut.
"We document that special lactic acids produced by bifidobacteria play a key role in keeping antibiotic-resistant bacteria at bay, which is important for reducing the risk of resistance genes being transferred to other bacteria in the gut. Resistance genes can jump from one type of bacteria to another, and the more bacteria with resistance that are present in the gut, the greater the chance that they will encounter other bacteria and transfer resistance genes to them,” says postdoc Ioanna Chatzigiannidou from DTU Bioengineering, who participated in the research project.
The study of gut bacteria is based on 547 stool samples from 56 children and their mothers, who were followed over a five-year period.
A matter of life and death for infants
Professor Susanne Brix Pedersen from DTU Bioengineering is the head of the research project and explains that the new knowledge about bifidobacteria can be better utilized in society when researchers have developed a rapid test for use in the first weeks of a child's life, so that parents can check whether their child already has these bifidobacteria naturally or would benefit from receiving a supplement containing them.
"It will be very important if we can strengthen their ability to handle antibiotic-resistant bacteria from the first weeks of a child's life. This is especially true in the first year of life where infants are exposed to many infectious diseases due to an immature immune system, and when it is a matter of life and death if they have many antibiotic-resistant bacteria, for instance the pneumonia bacteria Klebsiella pneumoniae, making it difficult to treat pneumonia with certain antibiotics," says Susanne Brix Pedersen.
There is a lot of research into antibiotic resistance, and Susanne Brix Pedersen is also involved in another study, BEGIN, which is based in the paediatric department at Aarhus University Hospital, where researchers are investigating whether a dietary supplement containing beneficial bifidobacteria can strengthen the immune system of newborn babies. So far, the trial has involved 300 women and their newborn babies, who are given either a placebo or a dietary supplement containing the special bifidobacteria.
Facts
Antibiotic resistance
Resistant bacteria that cannot be killed with antibiotics are a growing global problem, and although Denmark generally has lower resistance rates than many other countries, there are worrying trends – including in the treatment of infants.
Denmark has traditionally had a restrictive approach to antibiotic use, which has limited the development of resistance. However, antibiotic-resistant bacteria have been found in Danish infants, which emphasizes that the problem also exists here.