20 LISTENER NOVEMBER 5 2016
asthma, eczema and lactose intolerance;
type 1 and 2 diabetes; atopic disease; gas-
troenteritis; coeliac disease; hypertension;
otitis media; obesity; high blood pressure
and cholesterol; and sudden infant death
syndrome.
The World Health Organisation (WHO)
estimates nearly half of diarrhoeal diseases
and a third of respiratory infections in chil-
dren in low- and middle-income countries
could be prevented with increased rates
of breastfeeding. The WHO also estimates
increased breastfeeding would save the lives
of 800,000 children, most under the age of
six months, and US$300 billion each year.
Exclusive breastfeeding for the first sixmonths of life, followed by the introduction
of appropriate complementary foods, is also
a significant factor for reducing the risk of
childhood obesity, says the WHO.
THOUSANDS OF DISTINCT PROTECTORS
The health and economic effects of human
breast milk are hardly surprising given the
complexity of this living tissue – it contains
a vast array of complex nutrients and thou-
sands of distinct bioactive molecules that
protect against infection and inflammation
and contribute to organ development, mat-
uration of the immune system and creation
of a healthy microbiome.
In 2015, scientists from the Uni-
versity of California published
research on 524 newly discov-
ered protein molecules in human
breast milk, increasing the stag-
gering total of identified protein
molecules in the milk to more
than 1600. Yet the purpose of
many of these molecules is still
unknown.
Meanwhile, the first reports of cellswith stem-like properties in breast milk
emerged only in 2007, with confirma-
tion of breast-milk stem cells occurring
within just the past five years. This discovery
was met with excitement by large sectors of
the scientific community, but more for the
potential human breast milk may offer as a
more ethical source of stem cells than ones
from embryos, rather than their potential
role in the development of infants.
Indeed, far less focus has been placed on
understanding the role of stem cells or many
of the other cells found in breast milk. A
review in Nature, published last year, noted
that “cells are not a negligible component of
breast milk”, yet most research has focused
on factors influencing the nutritional com-
position of breast milk. As a result, exactly
what function the stem cells play is still
unknown, as is the nature and function of
thousands of other compounds in human
breast milk.
Perhaps most surprising to our genera-
tion is the relatively recent discovery that
breast milk contains millions of microor-
ganisms, along with oligosaccharides that
feed those microorganisms. These oligosac-
charides are not an incidental component
of breast milk; rather, they are the third
most abundant component in human
breast milk, suggesting they play a crucial
role in our well-being.
Researchers from Imperial College
London recently discovered that some
women’s breast milk contains an HMO
sugar molecule called lacto-n-difucohexa-
ose I that may protect newborn babies from
infection by the potentially life-threatening
bacterium known as group B streptococcus,
a common cause of meningitis in newborns
and a leading cause of infection in the first
three months of life.
HMOs feed friendly bacteria, encourag-
ing them to thrive and out-competeany harmful bacteria in the infant’s gut.
These sugars may also act as a decoy, fool-
ing the bacteria into thinking they are a
human cell that the bacteria then attempt
to invade. However, once the bacteria latch
onto the sugar, they are simply excreted
from the body.MESSING WITH THE FORMULA
Although there is still much to learn about
how each of these 150 or more HMOs
influence an infant’s microflora and futurehealth, some companies are already adding
certain HMOs to infant formula milk in the
absence of clear know ledge about how they
influence infants with vastly different genet-
ics, says Grayson.
Formula manufacturers are clearly hope-
ful of replicating human breast milk.
However, Imperial College London lead
researcher Dr Nicholas Andreas cautions it
will be difficult for infant formula to repli-
cate the complex mixture of sugars found in
breast milk. “These experimental formulas
only contain a couple of these compounds,
whereas human breast milk contains dozens
of different types.
“Furthermore, the quantity of sugars pro-
duced by the mother changes as the baby
ages, so that a newborn baby will receive
a higher amount of sugars in the
breast milk than a six-month-old.”
This is because breast milk is a
dynamic, bioactive fluid that
changes composition as the
infant grows, varies within
feeds and across the course of
the day, and varies between
mothers. And though many
mothers would be unaware
of the complexity of breast
milk, many understand
the importance of
breastfeeding their child,
if the high rates of breast-
feeding initiation are any
indication.
Still, althoughGENETIC REVOLUTION
Reports of cells with
stem-like properties in
breast milk emerged in
2007, with conirmation
occurring within just
the past ive years.
“Every mother produces
a unique pattern of
these 150 or more
oligosaccharides
- tailored directly
to her infant.”
Dr Nicholas Andreas and Massey
University’s Louise Brough.