 Y ddweud yw'r drosio cyfnod yma, sy'n Chico Pundio, ein bod yw'r ddeud yr unedig P.H.D yw'r ddweud yw'r ddweud yw'r drosio cyfnod o'r profesor David Cameron Smith. Chico'n dweud yw'r ddweud yw'r ddweud yw'r ddweud yw'r ddweud yw'r ddweud i'r cyfnod yma yn India sy'n dweud i'r New Zealand. Chico'n dweud yw'r ysgrifennu a'r ymddiadau cyfnod. maen nhw'n ystod yn ei wneud o'r llunio cydweithio ar gyfer yndyn nhw'n mwyaf, fel oedd yn ei gwybod yn ymddangosol i'ch holl o'r cydweithiau sydd yn cyrraedd cyflwyno ac mae'n bwysig i'ch gweledd iawn yn y Newzeo a Gweld yma. Yn y ffasenasiwm ymdegwyd, mae gennym y cyflwyno eich cyflwyno ar gyfer y mylwyr cyflwyno, ac yn fyrda i'r gwneud yn ffasenio y sydd wedi'i gallu'n arfer y bwysigol o bwysigol. Chi'n gael. Ddodolol, Frank, ac ddodolol, ti'n fawr yn ddweud ei wneud hynny a'r gwneud i'r fawr o'r cyflwyno i'r fwylltig. Yn y ffranc menwys, mae wneud ymddig yw unrhyw o bwysigol a'r gwmposisiwn. For human babies, mother's milk is everything. It's like a perfect cocktail of nutrient essential for their growth and development. Mother's milk has this remarkable property of changing its composition at every stage of lactation. It can change its composition if a child is boy or girl. It can change its composition if a mother is underweight or overweight. It can even change its composition if a child is born full term or pre term. In short, it's a food exclusively made for your child. And that's why majority of health professionals consider it so much more than just food. It is an intense process where mother sends biochemical signals to her child. In addition to providing all those essential nutrients, human milk contains lots of non-nutritive, bioactive compounds such as digestive enzymes, antimicrobial compounds, hormones and growth factors, which are essential for their survival and healthy development. By saying that having a child and raising a child is exciting, but challenging too. And I'm sure most of you will agree with me. When mother is stressed, she can possibly transfer those stress hormones to her child via milk. And because these little baby systems are still developing, these second hand hormones, or you could say these additional hormones, can affect their behavior and temperament differently. And all these effects can have different consequences for both boys and girls. Because stress feature modern life, or it's kind of an integral part of our modern life, we wanted to know what this modern life is doing to the composition of milk. So why are we interested in stress hormones? First of all, stress hormones are mainly consist of cortisol, the active hormone, cortisol, the inactive hormone. Apart from regulating the stress, they play an important role for the human development, such as fetal maturation, brain development, immune response and are also required for normal metabolism. But some recent studies have shown that stress hormones ingested via mother's milk can affect child's temperament and behavior differently. And these can have different impact on boys and girls. Traditionally, scientists have correlated maternal mood state with the stress level in her blood. But very little is known about the impact of maternal environmental factors on the stress level in mother's milk. And that's where my PhD comes in. So the main objective of my research was to identify maternal social, environmental and biological factors and identify their effect on the stress hormone level in their milk. I have studied a lot of social and biological factors, but today I'll only discuss about the most interesting one, such as mode of infant delivery, breastfeeding patterns, family structure, marital status or parental relationship, and seasonal variation which would account for environmental factors. And to do that, we collaborated with one of the university in Finland and obtained more than 800 breast milk samples. And getting more than 800 breast milk samples is a really big deal. And all those samples were collected when infants were three months old. So far, this is the first study which have investigated the impact of mode of infant delivery on mother's stress hormone level in her milk. And as you can see here, the x-axis shows the stress hormone level in mother's milk and the y-axis shows the groups we compared. So the white bar indicates the normal delivery, like where mother delivered babies via normal natural process of birth, whereas the black bar indicates the caesarean deliveries where mother had their babies via caesarean section or surgical procedure to deliver the babies. And the results of my studies have shown the significant increase in the milk of mothers who had caesarean babies compared to the ones who had normal deliveries, even three months after the birth of their child, something important to think about. Then we looked at another important factors, and that is breastfeeding. According to World Health Organization, breastfeeding is usually categorized into two main types, exclusive breastfeeding and partial breastfeeding. In exclusive breastfeeding, infants receive mother's milk, except the medication for the first few months of their life. And in the partial breastfeeding, they get the combination of both breast milk and formula milk. Again, in these graphs, as you can see, the x-axis indicates the stress hormone level in the mother's milk, whereas this y-axis shows the comparison between the group. So, the white bar indicates the exclusively breastfed kids, whereas the black bar indicates the partial breastfed groups. And contrary to our expectations, we found that breastfeeding preferences or patterns have no impact on the stress hormone level of mother's milk. But it wasn't the case when we looked at the social support structure of mothers. Out of all the social factors, we found that parental relationship or marital status or family structure are the most interesting one. In this marital status one, we divided our mothers based on their marital status. The white bar here indicates the mothers who were married, and this grey bar indicates the mother who were in the relationship. Either they were living together or de facto relationship, and the black indicates mothers who were single. And results of my studies have shown that mothers who were single, their milk had significantly high level of stress hormones in their milk compared to the one who were living with the husbands or partners. We further looked at the impact of family structure or family arrangement. Here we divided mothers or their milk samples in three groups again. First was the nuclear, the white bar indicates the nuclear family, which has same biological parents, whereas the grey bar indicates the blended one. And it has, one of the parents was a step parent, whereas the black bar indicates solo parent, where mother was on her own. And similar to parental relationship, we found the mothers who were single or who were living on their own, their milk levels had significantly high level of stress hormones compared to the ones who had some kind of support. So basically these results indicate importance of that, or maybe a big boohoo for that, that you are doing something. Even if you are vice or saying you are not doing enough, you are doing something. Then we looked at the seasonal variation, and in here we divided our mothers or maybe we divided our milk samples when they were collected. So the black bar indicates the samples which were collected in the winter season, whereas the white bar indicates when the milk samples were collected around the summer season. So again the results showed that milk samples, however we were quite surprised to see these results, that the milk samples which were collected during summer season, they had significantly high level of stress hormones compared to the ones we collected in winters. Why? We also wondered why, and it was my own assumption that maybe mothers were busy organizing more picnics and it's quite stressful. So what's the key message of my research? The key message of my research is that maternal environmental factors can have a significant impact on the milk composition. Particularly mode of delivery, seasonality and support system can affect the stress hormone level of mothers milk. Press milk is a remarkably complex fluid and because it is so ubiquitous in our environment, we often tend to take it for granted. There are several unanswered questions from my research which needs to be answered. The first and most important is that what are the effects of altered milk composition on the early life development and if there are any long term consequences to it. All these questions need to be answered and they can only be answered with the support from science and society and that's where you all come in. As a researcher, I want to bring results out of the lab to the normal people, policy makers and all the health professionals and inform normal New Zealanders how to make a better start to a healthy life. In the end, I would like to acknowledge my lab group, especially my supervisor David Cameron Smith and most importantly all the philanthropic fundings, Gravida, egg research and Ridditt Institute for funding my research and giving me this opportunity to explore the mysteries of human milk. Thank you.