Overview: Mammals and breast milk
Breast milk is an amazing and nourishing liquid food that has evolved over time to support the development of a baby. Humans belong to a group of specific animals called ‘Mammals’ and all species from this group produce milk. People are surprised when I explain that whales too produce milk and that these animals are therefore classified as mammals too; in fact, baby humpback whales require about 150 gallons of milk a day! Select this link Smithsonian channel to see a beautiful video of a humpback whale breastfeeding. This video was published by Smithsonian channel on February 4th, 2016.
Research has shown that milk evolved a very, very long time ago. Kazuhiko Kawasaki et al, 2011 who works in the Department of Anthropology, Pennsylvania State University explains, “that many slight genetic modifications of ancestral genes have created caseins, proteins vital to the sustained success of mammals.” This suggests that the origins of certain important proteins in breast milk actually have a very ancient origin. One of these ancient proteins are called casein, which helps to transport nutrients to the body to aid skeletal development. Thus, milk is produced by all mammals of different shapes and sizes; It is an extremely ancient substance that has evolved slightly over the years to make it a super-nutritious milk, which is needed for the first few months or years of your baby’s life.
“Not only is breastfeeding good for the infant but it is also important for the mother.”
Why should mothers breastfeed?
An article written on Webmd looks at the benefits of breastfeeding for new mothers. Breast milk contains vital vitamins, proteins and fats needed for the baby to grow healthy. It is easier to digest compared to formula and contains the mother’s antibodies that strengthen the baby’s immune system. The risk of developing asthma and allergies is much lower for breast fed infants. Those who are exclusively fed for the first 6 months are also associated with low risk of developing diseases such as respiratory diseases and ear infections.
What is also crucially important about breastfeeding is that it helps in aiding a secure attachment between the infant and primary caregiver. The skin-to-skin contact, closeness and eye contact is so important in allowing the development of a strong, emotional maternal bond. This is important in supporting the infant’s ability to form positive, emotionally-sound relationships as an adult.
Not only is breastfeeding good for the infant but it is also important for the mother. It helps with weight loss, ensuring the uterus wall returns back to its pre-pregnancy size, reduces bleeding and those who do not breastfeed are more likely to develop certain cancers. Lastly, it is cheaper than buying formula/ all the equipment that goes with it and you also get that special time to bond with your baby.
“Breast milk is more alive than you may think.”
Breastfeeding is crucial for your baby to develop a healthy gut microbiome
What is a microbiome? Julian R. Marchesi, Professor of Human Microbiome Research at Cardiff University and Professor of Digestive Health at Imperial College London, describes it as, “the community of micro-organisms living together in a particular habitat. Humans, animals and plants have their own unique microbiomes, but so do soils, oceans and even buildings.”
Breast milk is more alive than you may think. It is heavily well known now that breast milk harbours its own bacterial community. The bacterial community is thought to be influenced by a number of different factors such as, gestational age (how far along the pregnancy is), environment, geography, antibiotics and the act of breastfeeding itself. When the baby is breastfed, the back flow of blood into the mammary gland (breast) contains the bacteria from the baby’s mouth.
Elena Biagi et al a researcher at the University of Bologna, Bologna, Italy recruited 16 mother-infant pairs who were born with a gestational age between 32-34 weeks. This means that the infants are not able to latch onto the breast until later on. Thus, the infants were fed the mothers-own milk she expressed or they received donor milk. The researchers encouraged the mothers to breastfeed to ensure her breast continue to produce milk. When the infants grew a little older, with adequate support, they began to latch and the mother could now breastfeed her baby. The researchers observed the changes in the baby’s microbiome before and after latching/ actual breastfeeding to see how it changed.
“latching and actual breastfeeding could help shift the gut microbiome of these infants toward the health-associated profile of full term infants.”
Researchers found that the mother’s milk microbiome changed when the baby began to breastfeed. The back flow of milk from the baby’s mouth (containing the baby’s own unique oral bacterial community) into the mammary gland is thought to be the reason for this.
Those mothers who did not breastfeed directly had a, “milk bacterial community with lower diversity and dominated by Staphylococcus…On the contrary, milk samples taken after latching harbored more diverse microbial communities.” The bacteria that was commonly found was Streptococcus and Rothia, these are typical oral microbes found in children. So, why does this all matter? The researchers showed “that different types of microbial communities in milk are associated with different features in the infant’s gut and mouth ecosystems.” The bacterial community that was associated with breastfeeding “corresponded to the highest percentages of Bifidobacterium in the infant’s gut” This is the most important group to reside in the gut of an infant for healthier development.
Thus, this shows that “latching and actual breastfeeding could help shift the gut microbiome of these infants toward the health-associated profile of full term infants.” This highlights the importance of breastfeeding in developing a healthy gut for infants.
The researchers conclude that, “taken together, our observations strengthen, from a novel, microbiome-centred, point of view, the importance of encouraging not only exclusive human milk feeding, but also an early start of actual breastfeeding in preterm infants, as the infant’s latching to the mother’s breast appears to be an independent factor associated with a health promoting profile of the infant gut microbiome.”
Kazuhiko Kawasaki, Anne-Gaelle Lafont, Jean-Yves Sire. 2011. The Evolution of Milk Casein Genes from Tooth Genes before the Origin of Mammals. [ONLINE] Available at: https://academic.oup.com/mbe/article/28/7/2053/1047188. [Accessed 7 March 2019].
WebMD. 2019. Breastfeeding Overview. [ONLINE] Available at: https://www.webmd.com/parenting/baby/nursing-basics#1. [Accessed 7 March 2019].
Elena Biagi, Arianna Aceti, Sara Quercia, Isadora Beghetti, Simone Rampelli, Silvia Turroni, Matteo Soverini, Angelo Vittorio Zambrini, Giacomo Faldella, Marco Candela, Luigi Corvaglia and Patrizia Brigidi. 2018. Microbial Community Dynamics in Mother’s Milk and Infant’s Mouth and Gut in Moderately Preterm Infants. [ONLINE] Available at: https://www.frontiersin.org/articles/10.3389/fmicb.2018.02512/full. [Accessed 7 March 2019].
Julian R. Marchesi. 2017. What is a microbiome. [ONLINE] Available at: https://microbiologysociety.org/blog/what-is-a-microbiome.html. [Accessed 7 March 2019]