Expert opinion

Antibiotics are designed to kill the bacteria that make us sick. We are increasingly aware that they also killing the bacteria that makes us healthy – the “good bacteria”. There are many consequences of this: our gut microbiota help us extract energy from food, and they regulate how much weight a baby gains.

We wanted to look at the possibility of reducing allergies in infants, via the mother. We gave nutritional counselling to the mothers in the study from the first trimester of pregnancy alongside a probiotic combination. The study continued from this point, through the entire pregnancy, birth and until the mother stopped breastfeeding. We were interested in the outcomes for the child.

Human milk oligosaccharides (HMO) are complex sugars that mothers produce in very large quantities in their breast milk. We can think of them as fibres, and the baby cannot consume them. One of goals of the oligosaccharides is to alter the gut bacteria of the infant.

I first came into contact with HMOs in 1984 when researching alongside my supervisor who was very interested in glycoproteins, carotenoids and oligosaccharides. He had studied for his PhD under Richard Kuhn, the Austrian-German biochemical pioneer who classified HMOs via clinical trials for the first time in the 1950s.

We have been studying human milk for many decades, and recently discovered that it contains indigestible material, which was very interesting. Mothers appear to be synthesizing molecules that go right through the baby. We decided to investigate this in detail.

The colonizing bacteria have a profound impact on gastrointestinal function, as well as the immune function. It is particularly important at the initial stage of colonization because this is when the infant is developing defences against bacteria plus the prevention of immune related disease.

There are three major areas that need to be taken into consideration when looking at whether infants should receive fortified complementary nutrition or micronutrient supplements. These approaches would only be necessary if the infant was deemed to be undernourished.

When deciding what infant formula to use, it is important to understand that different formulas offer different levels of protein hydrolyzation whereby proteins are broken down in size and sequence. There are two main levels of hydrolyzation used in infant forumulas: some extensively hydrolyze proteins and some only partially hydrolyze them.