Biochemistry According to a study, seal milk has medical potential
Grey seal milk is as complex in its composition as human breast milk - and could even be added to formula in the future. This is shown by a study published on Tuesday, in which Swiss researchers were also involved.
25.11.2025, 17:00
SDA
"The study shows that we have massively underestimated the complexity of non-human milk," said study leader Daniel Bojar from the University of Gothenburg (Sweden) to the Keystone-SDA news agency. He attributes this to the fact that research to date has mainly focused on domesticated animals, whose milk has lost diversity through breeding. The study was published in the journal "Nature Communications".
The study focused on complex sugars, so-called milk oligosaccharides. These strengthen the immune system, promote healthy gut bacteria and protect babies from harmful germs.
Seal milk molecules for bottle powder
The researchers found 332 different such oligosaccharides in the seal milk, 166 of which had never been described before. Some of these molecules reached a size not previously observed even in human breast milk.
Some of the newly identified oligosaccharides proved to be strong stimulators of human immune cells in the laboratory. "In the future, such molecules could be added to bottle powders or even used therapeutically in adults," explained Bojar.
How to milk seals
For the study, the researchers milked five Atlantic grey seals (Halichoerus grypus) on the Isle of May in Scotland. Samples were taken from the seals at four points during the nursing period.
But how do you actually milk a seal? "It might not be the traditional image you have in mind when you hear the word 'milk'," Bojar told Keystone-SDA. In practice, wild seals are first put under anesthesia. They are then administered the hormone oxytocin, which stimulates the flow of milk and thus enables the researchers to extract milk from the teats in a controlled manner.
Researcher Carmen Cori from the University of Basel was involved in the study from Switzerland. She was responsible for the chemical characterization of newly discovered milk oligosaccharides and analysed their structure in the laboratory.
