Scientists from MIPS have discovered that human breast milk forms into highly
organised structures during digestion in the body. Their study was published
in Angewandte Chemie – a leading international chemistry journal.
Researchers believe this self-assembly process
might be key to releasing the nutrients in
human breast milk to ensure an infant’s
healthy development.
The findings, which show for the first time the
structure of human breast milk during digestion,
could potentially be used to develop new food
supplements and nutritional formulas that are
easily digested.
Funded by the ARC and led by Dr Stefan
Salentinig and Professor Ben Boyd from MIPS,
in collaboration with the Mercy Health Breastmilk
Bank, the team looked at the nanostructure of
milk to gain new insights into how milk interacts
with the digestive system.
Lead researcher Professor Ben Boyd said while
the nutritional value of human breast milk and
other types of milk are well known, little research
has been conducted until now into the detailed
structure of milk during digestion and how the
fats in milk interact with the digestive system.
“Human breast milk is key to the survival and
development of humans, yet until now we had
no idea of the rich structure formation when it
is digested,” he said.
“Finding out what happens to milk during digestion
will allow us to better understand how the essential
nutritional components for building brain tissue and
other parts of the body are absorbed. Potentially
we could use these findings to design more
effective food and nutritional supplements.”
The research team developed an ‘artificial
tummy’ to simulate digestion, and conducted tests
that mimicked people with an underdeveloped
digestive system such as a pre-term infant.
The structures formed in the digesting milk were
then studied using specialised instruments at
the Australian Synchrotron, revealing that highly
organised structures are formed from the
by-products of milk when digested.
Professor Boyd said results indicated that,
in people lacking normal mechanisms to aid
digestion, the structure of milk adapts to overcome
this. The finding may be particularly important
for premature infants, whose digestive system
is often not fully functional.
“We suspected that the fats in milk form structures
to aid the digestive process but until now we’ve
not been able to prove this. The Synchrotron was
essential to this work because it allowed us for the
first time to see what happens during the digestive
process,” he said.
”We need to do further work. But this study
suggests that if you’re lacking normal mechanisms
to aid digestion, there is a compensatory system
present in human breast milk that adapts to allow
those individuals to survive.”
The research into human breast milk builds on
previous work by the MIPS team on cow’s milk,
which also revealed a highly organised structure.
Professor Boyd said the major difference between
cow’s milk and human breast milk is that the latter
contains enzymes that enable the highly organised
structures to form all on their own. With cow’s milk,
to induce digestion, something needs to be added
– an enzyme called lipase, to initiate the
digestive process.
“In both cases, the highly organised structures
are formed on digestion of mammalian milk,
whereas subjecting soy milk to the same digestion
process does not result in the formation of these
structures,” he said.
“The next step is to actively link the formation of
these very interesting colloidal structures to the
absorption of digestion products. We expect that
different structures will have different abilities to
transport and release nutrients.”
Understanding this link will allow us to design more
nutritious supplements and infant formulas, as well
as give new insights into why these structures form
under some conditions and not others.
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