Dr. Carina Venter: And so today I'll be talking to you about the role of human milk oligosaccharides in reducing allergy risk. And so the objectives of my talk today really is to define human milk oligosaccharides, and describe their key structural features. Explain how HMOs support the development of the infant immune system critically review the current evidence linking HMOs to reduced allergy risk in early childhood. And then, really, you know, the practical things is, how can we apply our evidence to daily clinical practice? And so the 1st topic, then, is to define human milk oligosaccharides, or HMOs. And I'm going to start with a question: which of the following statements about HMOs is true. HMOs are simple sugars, primarily used by the infant for direct energy. HMOs are the second, most abundant, solid component in human milk. HMOs act as prebiotics by promoting growth of beneficial gut microbes, like Bifrobacteria and HMos are produced in the infant's gut in response to breastfeeding. And so we'll give you a few seconds just to think about that. And so interestingly, the majority of you got it right. Hmos act as prebiotics by promoting growth of beneficial gut microbes like bifirobacteria. And I'm really going to talk about that repetitively and a number of times today. So let's look at HMOs, HMOs are indigestible complex glycans or carbohydrates found in human milk. It is the 3rd most prevalent solid component of human milk after lactose and lipids, so not the second most. The concentration is the highest in colostrum. And just 2 days ago I presented data with Valerieval Hassel from Perth, in Australia. Our paper is for final review, where we actually showed that children who consume colostrum in the 1st few days of life have less cow's milk allergy, and we think at least that is merely because of the HMO concentration in colostrum. And then over time, HMO abundance decline. I'm going to show you that 2 of them actually decline. One actually increases. But the net effect is that Hmo abundance decline over the course of lactation deflecting an infant's developmental needs. And I'm also going to show you when we get to the practical session in the end is that there are some foods that can act as prebiotics. And so, perhaps, as we're getting babies established on a more solid food diet. They may actually need the probiotics in diet, more so than they need the Hmos or the Prebiotics, as they heavily rely on them, particularly in the 1st 6 months of life when they are not eating. So there are 3 major types of Hmos. But actually we have 200 distinct structures. And the number of structures actually differ between mothers from different populations, mothers from different diets, although we haven't actually been able to look at the direct effect of diet versus hmos, and it also can differ between 2 different mothers, and also in the same mother, between different feeds. so we can see that the Hmos can really differ, and can be very varied, depending on the feed that the infant is getting. You know, you can read about how they are produced and how they are elongated. But the major classes are the following 3, the one is the fucosylated HMOs. So often we refer to that as 2-FL in infant formulas. the sialylated Hmos, which is the 6-SL, and then also the neutral HMOs. And I have a question about that later on in the talk which is the Lnt so 3 major types that we are actually seeing. Then changes in Hmo levels over the course of lactation, dynamic changes. As I said, they change over time, and it's particularly the 2 Fl and the LNT that actually decline over the course of lactation. But the 3-FL actually rises over the course of lactation, and as I've already mentioned, that we see population variation and that overall HMO concentrations and specific profiles varies between mothers and populations and also feed to feed.