Immunology of breast milk

Abstract

In the critical phase of immunological immaturity of the newborn, particularly for the immune system of mucous membranes, infants receive large amounts of bioactive components through colostrum and breast milk. Colostrum is the most potent natural immune booster known to science. Breastfeeding protects infants against infections mainly via secretory IgA (SIgA) antibodies, but also via other various bioactive factors. It is striking that the defense factors of human milk function without causing inflammation; some components are even anti-inflammatory. Protection against infections has been well evidenced during lactation against, e.g., acute and prolonged diarrhea, respiratory tract infections, including otitis media, urinary tract infection, neonatal septicemia, and necrotizing enterocolitis. The milk's immunity content changes over time.In the early stages of lactation, IgA, anti-inflammatory factors and, more likely, immunologically active cells provide additional support for the immature immune system of the neonate. After this period, breast milk continues to adapt extraordinarily to the infant's ontogeny and needs regarding immune protection and nutrition. The need to encourage breastfeeding is therefore justifiable, at least during the first 6 months of life, when the infant's secretory IgA production is insignificant.

Identification of red blood cell antibodies in maternal breast milk implicated in prolonged hemolytic disease of the fetus and newborn

“…However, the recommendation to stop breastfeeding must be weighed against the known benefits of breastfeeding. Colostrum and breast milk are a rich and cost‐effective source of nutrients, containing high concentrations of protective immunologic factors that provide passive immunity to the infant . The decision to cease breastfeeding should be made only after thorough discussion between the family and provider and must take into consideration the infant's clinical picture.…”

“…Colostrum and breast milk are a rich and cost-effective source of nutrients, containing high concentrations of protective immunologic factors that provide passive immunity to the infant. 15 The decision to cease breastfeeding should be made only after thorough discussion between the family and provider and must take into consideration the infant's clinical picture. In this series, the mothers of the two infants with less severe hemolysis were able to continue breastfeeding and wean at their desired time.…”

Experiencias y creencias de madres sobre la lactancia materna exclusiva en una región de México

“…Circunstancia también comentada en otros trabajos. [8][9] Las madres comentan de igual manera que ellas notan cómo la leche fortalece el sistema inmune de sus hijos haciéndolos más fuertes y resistentes a infecciones, beneficios percibidos por ellas, esta apreciación coincide con lo reportado anteriormente al indicarse que la leche materna es la responsable de mantener el nexo inmunológico madre-hijo, al suministrarle a éste elementos protectores, células y factores solubles en su mayoría, los cuales en el neonato están ausentes, situaciones similares en cuanto a la protección en un amplio rango de enfermedades, sobretodo infectocontagiosas, lo que concuerda con trabajos reportados en poblaciones semejantes [10][11] y que forma parte del discurso con el que el personal médico cree convencer a las madres para que inicien y mantengan esta práctica. 12 Las participantes nombran a la familia en su discurso como un promotor importante para comenzar y continuar con la práctica situación observada en otro estudio 13 lo que indica una aceptación total hacia la lactancia materna como la mejor y más sana opción.…”

Maternal immunization: where are we now and how to move forward?

“…In addition to the protection provided by maternal IgG antibodies transferred through the placenta, high concentrations of maternal IgA and to a lesser extent IgG and IgM, are excreted in the colostrum and breast milk [20]. For instance, vaccination with Tdap in the second or third trimester of pregnancy, or immediately after delivery, increased the levels of pertussis-specific IgA antibodies in breast milk [21].…”

“…Breastfeeding therefore represents another mode of transferring antibodies to new-borns. Secreted IgA is an important part of host defence at the mucosal level, notably in the gastrointestinal and respiratory tracts [20]. IgA transferred through breast milk help protect infants against enteric infections and, in infants born to influenza-vaccinated mothers, against respiratory illness with fever for at least 6 months after birth [20,22].…”