Breastfeeding Resources

HMOs act as prebiotics to fuel gut bacteria to support digestion and help develop a newborn’s microbiome. They are important to the immune system, helping to prevent infection, reduce the risk of diarrhea and respiratory illnesses, regulate inflammation and strengthen the gut barrier to limit the absorption of potentially harmful substances. HMOs also provide nutrients that promote healthy brain development.

These small proteins help the healthy development of a newborn’s immune system. Some cytokines have anti-inflammatory properties, reduce allergy and autoimmune risks and protect against infections. In contrast, others support gut health by strengthening gut barriers and promoting the growth of beneficial gut bacteria. Early exposure to cytokines through breastfeeding may even provide long-term benefits, such as reducing the risk of asthma and obesity as the baby grows.

A lysozyme is an antimicrobial enzyme found in breast milk that protects newborns by breaking down the cell walls of harmful bacteria and helps support gut health. The enzyme reduces gastrointestinal and respiratory infections in newborns and shapes a healthy gut microbiome by destroying harmful bacteria while preserving beneficial bacteria.

Sometimes called “liquid gold,” colostrum is the nutrient-dense milk produced during late pregnancy and in the first few days after birth. It is thick and yellowish, providing essential proteins, vitamins, minerals and other growth factors to help newborns get off to a strong nutritional start. Colostrum is also high in antibodies, boosting the newborn’s immunity and protecting against infections. For most, colostrum will shift to mature milk within two to four days postpartum.

Lactoferrin is a glycoprotein found in breast milk, particularly colostrum. (A glycoprotein is any protein molecule with a carbohydrate (sugar) attached, acting as a communication piece in cell-to-cell interactions.) Lactoferrin offers antimicrobial effects by binding to iron, limiting bacterial and fungal growth. It also supports the immune system, boosting immunity and gut health while providing anti-inflammatory and antioxidant properties.

Infants born prematurely (before 37 weeks) are very vulnerable, but preterm breast milk is tailored to meet their needs with higher levels of proteins and fats to fuel rapid growth and development. The increased nutrient content of preterm milk supports the underdeveloped organs and systems of preterm infants, particularly the brain and nervous system. In addition, preterm milk provides enhanced protection for their fragile immune systems. Preterm breast milk also adjusts to a baby’s needs over time, prioritizing higher nutrient density and protective factors initially and transitioning to resemble mature milk. While preterm milk is a fantastic support for premature infants, it can be a challenge for mothers to produce due to factors such as delayed lactation, stress from a NICU stay or the inability of a preterm infant to breastfeed. To maintain milk production, frequent pumping and lactation support are often needed. Pasteurized donor milk can be used to supplement or replace maternal milk; however, it may lack some of the specialized components that maternal milk provides. To ensure preterm infants receive optimal nutrients and support from breast milk, navigating these challenges with health care providers and lactation consultants is crucial.

Foremilk and hindmilk represent the gradual changes in the composition of breast milk during a single feeding. Foremilk is the thin, watery milk at the start of a feed, appearing translucent or bluish. It is high in lactose and water content, quenching the baby's thirst and providing quick energy. Hindmilk comes at the middle or end of a feed, appearing thicker, creamier and more yellowish. It is higher in fat, calories and proteins to aid in weight gain, growth and the feeling of fullness after feeding. The benefits of hindmilk are best accessed by longer feeding on one breast, helping provide balanced nutrition for the newborn. If a baby is getting too much foremilk (either from short feeds or frequent breast-switching), they may experience gassiness or frothy stools due to excess lactose. 

The caloric content of breast milk can be influenced by several factors, such as the stage of lactation (which affects colostrum versus mature milk) and whether it is foremilk or hindmilk. The mother’s diet also influences caloric density: higher fat intake increases calorie intake, while malnutrition lowers it. Even the time of day affects density, with evening and nighttime feedings often having slightly higher fat content, thereby increasing caloric density. Additionally, feeding patterns are another factor to consider, as frequent feedings may reduce fat content while longer feeding intervals boost hindmilk and caloric density.

Tongue-tie, medically known as ankyloglossia, is a congenital condition where a short or tight band of tissue connects the bottom of the tongue to the floor of the mouth, limiting tongue movement. A tongue-tie can cause difficulties with breastfeeding, speech interference or potential dental problems. This condition affects about 4% to 11% of newborns and is more commonly found in males. Treatments for tongue-tie may include a frenotomy (a quick clipping of the frenulum) for severe cases or support and/or therapy for milder cases.