Formula for success lies in special sugars
Molecules in mother’s milk are key to breakthrough in feeding infants
The molecules that make mother’s milk one of nature’s most nutritious foods could hold the secret to a blockbuster infant formula worth billions.
Scientists have discovered that 200 special sugars known as human milk oligosaccharides (HMOs), found only in mother’s milk, are the key to fighting bacteria, and may provide building blocks for the brain.
HMOs would be a major ingredient in a new generation of infant formula.
There are juicy profits on the line. With a $55-billion global market, baby food is a big business and it continues to grow as formula feeding spreads in the developing world.
“It turns out that antibodies in human milk are not what’s defending the baby against diseases. It’s these sugars, and the antibodies are just the frosting on the cake,” says Dr. David Newburg, a biology professor at Boston College and a founder of Glycosyn in Boston, one of the companies spearheading the research.
HMOs could hold the key to avoiding necrotizing enterocolitis, or NEC, a bacterial disease that affects about 10 per cent of premature babies and destroys their guts. NEC is fatal in one in four cases, and it is mostly preventable. Breastfed babies are almost 10 times less likely to get NEC than formula-fed ones.
Newburg says HMOs also could help adults fight travellers’ diarrhea, and even superbug infections such as C. difficile. But before HMOs’ benefits can be tested on humans, they have to be produced in sufficient quantities under approved conditions.
Glycosyn is among several companies trying to do this. Its rivals include Glycom of Denmark, Germany’s Jennewein and Belgium’s InBiose.
“We know how to make more than a handful of HMOs,” Newburg says. “Many of the major formula companies are actively investigating the possibility of adding these sugars into formula.”
In Canada, only 26 per cent of women breastfeed at six months, according to Statistics Canada. In countries such as Norway the breastfeeding rate is 80 per cent.
Some researchers remain concerned that too little is known about HMOs to offer them to the newborn in a form other than mother’s milk.
HMOs were discovered in the 1950s, but their full benefits to babies became apparent much more recently. HMOs are sugars made out of molecules linked together into chains that resemble beads on a string. Together these HMOs weigh 15 grams per litre, accounting for more weight than the total protein content of milk.
Unlike protein, fat or lactose, which is a different kind of sugar, HMOs do not nourish the baby. Indeed, they are indigestible to humans. Instead, HMOs provide nutrients for the baby’s gut bacteria, such as Bifidobacterium infantis, that help shape a balanced colony of microbes known as the microbiome.
Microbiome plays a crucial role in keeping humans healthy, and scientists believe that changes in its composition could be a contributory factor to a number of diseases including diabetes, allergies and even autism.
Research shows that HMOs can act as natural antibiotics, sticking to and mopping up bad bugs before they can do any harm.
While biotech entrepreneurs are eager to turn HMOs into milk-formula supplements, it has not been easy.
“The problem is that you do not find many HMOs outside human milk. And I don’t think a lot of moms will volunteer to be on a mommy farm to make these sugars,” Newburg says.
Only recently did it become possible to create HMOs from scratch in amounts suitable for industrial use. Newburg says the most promising approach is a process known as biological synthesis, where microbes are genetically engineered to produce certain HMOs. The HMOs can then be isolated as pure compounds without toxic byproducts.
For now, formula makers are taking a different route, adding other sugars made from regular cow’s milk, called galactooligosacharides, or GOSs, to their products.
Health Canada approved the new formula in 2012. Makers such as Similac have advertised that GOSs “act like food for the beneficial bacteria.”
But GOSs are structurally different from HMOs. The European Food Safety Authority has said there is no evidence they offer infants any benefits.
Some worry that adding anything less than the full suite of HMOs to infant formula will open a new can of worms.
“That is my biggest concern,” says Lars Bode, a professor in pediatrics at the University of California in San Diego who has been doing research on HMOs for 15 years. Bode says HMO sugars work in harmony, fulfilling different functions in a finely tuned balance.
“If you only give one, then you are shooting the system out of balance all of a sudden.”