Healthcare (Commonwealth Union) – Scientists at the University of Birmingham have found that helpful bacteria in babies’ guts use an unexpected tool to reach nutrients in breast milk. The finding could eventually help improve infant formula. The research was published on 2 November in the journal Nature Communications. It offers new insight into how the first communities of gut microbes take shape in early life.
Every person carries trillions of tiny organisms in their digestive system, known together as the gut microbiome. These microbes help break down food and play a role in keeping the body healthy. In newborns, this community is only just beginning to form. Among the first to settle in breastfed babies is a group of bacteria called Bifidobacterium, which are widely considered beneficial. Certain sugars in breast milk are believed to encourage these bacteria to grow.
The new study focused on an enzyme called PNGaseA. Enzymes are proteins that work like microscopic tools, speeding up specific jobs inside living things. This one is normally found in plants and animals, where it helps recycle important parts of cells. It has not usually been linked to the activities of microbes in the human gut.
The Birmingham team, however, found that some types of Bifidobacterium make this enzyme and use it to get food. The bacteria’s target is a particular kind of sugar in breast milk. These sugars are attached to short chains of protein pieces, a bit like sweets still stuck to their wrapper. The enzyme snips the sugars free so the bacteria can eat them.
Dr Lucy Crouch, who led the study, said the result shows how complex the community of microbes in milk-fed infants really is. She said the team was genuinely surprised to discover that gut bacteria use this enzyme to reach nutrients. She added that doing so may help a healthy bacterial community to grow.
The work also highlights how important some little-studied nutrients may be for a healthy microbiome. The researchers found that the enzyme only unlocks sugars attached to short protein chains. These are present in human breast milk but are not found in formula milk.
Dr Crouch explained that some parts of breast milk cannot yet be truly recreated artificially for use in infant formula. She said that identifying everything that helps “healthy” bacteria become established could point to ways of making formula as close to human milk as possible. In her view, that would give a baby’s natural gut microbes everything they need to settle in and thrive.
A co-author of the study, Professor Ramón Hurtado-Guerrero of the University of Zaragoza in Spain, pointed to another achievement. The team produced the first detailed picture of this type of enzyme gripping one of its targets, a sugar attached to a protein fragment. This shows how the enzyme recognises both the sugar and the protein piece it is attached to. Professor Hurtado-Guerrero said the picture also offers clues about how related enzymes might recognise their own targets.
The university said the work is a first step. Because it is the first time this kind of enzyme has been characterised in this role, it will take further research to fully understand how breast milk shapes a healthy gut community in babies. The findings may eventually help scientists design future formulas that include “prebiotics”. These are ingredients that feed beneficial bacteria, and they could help babies who cannot get human breast milk.
It is important to keep the findings in perspective. This is a laboratory study of how one enzyme works, not a trial of a new product, and no new formula has been announced. Dr Crouch’s wording was also careful: she said the enzyme “potentially” contributes to a healthy community, which suggests more work is needed to confirm how large its role is.
Still, the discovery adds a missing piece to a puzzle scientists have been working on for years: why breast milk is so good at nurturing a baby’s gut. By showing that a familiar enzyme has an unfamiliar job, the research may help shape how infant nutrition is designed in the future.
