Grew Three Times in Just 17 Days: More "Intense" Than Human Breast Milk - The Ultimate Seal Milk That Sends Pups Into the Sea in 17 Days

Was the "Strongest Milk" Not Human but Seal?

"Human breast milk is the most complex"—this has long been the prevailing thought.
However, a recent paper is turning this notion on its head. The star of the study is the Atlantic grey seal living in the North Atlantic. It turns out that this wild animal's milk is far more complex and "high-performance" than human breast milk.Nature

The research was conducted by a team from the University of Gothenburg in Sweden, among others, and was published in the journal Nature Communications. By employing glyco-biology (glycoscience) methods to thoroughly analyze the oligosaccharides in seal milk, they discovered 332 types of oligosaccharides. Human breast milk is known to contain about 250 types of oligosaccharides, so this is approximately 33% more.EurekAlert!

Even more astonishing is that many of these oligosaccharides have entirely new structures previously unknown. They also discovered a massive molecule with up to 28 sugars linked together, reported as "the largest milk oligosaccharide ever found."Nature

Seal pups thrown into the sea after 17 days

Why is seal milk so "enhanced"?

Atlantic grey seal pups are born on rocky islets. The nursing period lasts only about 17 days. During this time, they must nearly triple their body weight and develop thick blubber and a robust immune system. Once nursing ends, the mother suddenly disappears, and the pup must dive into the icy North Atlantic and survive on its own.Nautilus

Compared to the several months human babies spend "sleeping, drinking, and growing," seal pups have a short-term battle. This is why they need "doping-level" milk that delivers maximum effect in a short period.

Not just calories: The hidden star, "oligosaccharides"

When people think of "milk," they might imagine fats, proteins, and calcium. But this time, the spotlight is on the component known as oligosaccharides, which are present in only small amounts.

Oligosaccharides are not just sweeteners. Recent studies have shown that they

• serve as food for gut bacteria, increasing beneficial bacteria

• prevent pathogens from attaching to the gut, protecting against infections

• regulate immune cell functions, controlling inflammation

and perform other roles.EurekAlert!

In the seal study, it was also shown that some oligosaccharides inhibit bacterial biofilm formation and affect the immune system. Simply put, it's like having "security software for the gut and immune system" built into the milk.Nature

Milk "recipes" evolve with the nursing period

The research team repeatedly collected milk from wild Atlantic grey seals on an island off Scotland throughout the nursing period, tracking changes in its composition.EurekAlert!

The results revealed milk that becomes more diverse over time. In the first few days, specific oligosaccharides are abundant, setting the "initial settings" for the pup's gut and immune system. Then, different types of oligosaccharides increase, shifting to a phase that protects against environmental pathogens.

In human breast milk, it is also known that the composition balance changes between the "colostrum" immediately after birth and the milk months later. Similarly, in seals, extremely precise timing control is being conducted.Nature

Was the belief that "human breast milk is the strongest" a misconception?

This paper was introduced by Nature Portfolio's official X account and science media C&EN, creating a buzz in the research community's social media.X (formerly Twitter)

 

Nature Portfolio's post explained that "Atlantic grey seal milk has been shown to have oligosaccharide complexity comparable to human breast milk," and many researchers and science fans reposted it.X (formerly Twitter)

On LinkedIn, one of the co-authors expressed joy, stating, "We found the largest milk oligosaccharide with 28 sugar units ever" and "It dynamically changes throughout the nursing period, just like human breast milk."linkedin.com

One comment received was,

"There is still much to learn about milk oligosaccharides. We want to understand more about their nutritional and defensive roles."linkedin.com

This reflects a growing awareness among experts that "milk oligosaccharides are an unexplored frontier."

From general social media users,

• "I reconsidered the assumption that human breast milk is the 'strongest.'"

• "Instead of supplements for babies, we should first understand milk itself."

• "But I hope we never end up overharvesting seal milk."

These are common reactions (summarized to reflect typical trends).

In a sense, this research is **news that gently shakes a "human-centered" perspective**.

How will this connect to the development of formula milk and medicine?

There are no plans to give the oligosaccharides found in seal milk directly to human babies. Researchers aim to understand their structure and function, then synthesize or apply molecules with similar functions.EurekAlert!

Specifically,

• high-performance formula milk for premature or low-birth-weight infants

• prebiotic foods to improve gut health

• new anti-infection treatments that inhibit biofilm formation by pathogens

These applications are being considered. Seal milk serves as a "blueprint," and there is no need to milk wild animals. Many users on social media emphasized this point, advocating that "we should apply the knowledge learned while protecting the health and ecosystems of seals."

Seeing beyond cuteness: The "wisdom" of wild animals

When it comes to Atlantic grey seals, photos of fluffy white pups sleeping beside their mothers are popular, a staple of "cute animal content." This study visualized the **advanced "milk engineering"** crafted by evolution behind those images.Nautilus

Articles from the New York Times and other media worldwide have introduced this research with angles like "Wild Milk Rivals Human Breast Milk" and "The Ultimate Baby Food Born from the Harshness of the Sea."sciurls.com

Behind the milk and formula we pick up at the supermarket lies such a **"natural history of milk innovation."** Imagining this might make that familiar glass seem a bit different.

"To see milk is to see the strategy of life"

What was revealed this time is not a simple ranking of "milk stronger than human breast milk."

• Seals surviving in the rough North Atlantic

• Humans with long child-rearing periods

• What risks need to be prepared for in each environment

This difference is distilled into specific molecular designs in the form of milk—this is what the research teaches us.

Many voices on social media expressed surprise, saying, "There is still so much we don't know about our own bodies and other animals."

Seal breast milk is just one example of the diverse "parenting strategies" life on Earth has devised. Unexpected milks and bodily fluids from various creatures might continue to update our common knowledge.