A Review of the Immunomodulating Components of Maternal Breast Milk and Protection Against Necrotizing Enterocolitis

Abstract

Breast milk contains immunomodulating components that are beneficial to newborns during maturation of their immune system. Human breast milk composition is influenced by an infant’s gestational and chronological age, lactation stage, and the mother and infant’s health status. Major immunologic components in human milk, such as secretory immunoglobulin A (IgA) and growth factors, have a known role in regulating gut barrier integrity and microbial colonization, which therefore protect against the development of a life-threatening gastrointestinal illness affecting newborn infants called necrotizing enterocolitis (NEC). Breast milk is a known protective factor in the prevention of NEC when compared with feeding with commercial formula. Breast milk supplements infants with human milk oligosaccharides, leukocytes, cytokines, nitric oxide, and growth factors that attenuate inflammatory responses and provide immunological defenses to reduce the incidence of NEC. This article aims to review the variety of immunomodulating components in breast milk that protect the infant from the development of NEC.

The Immature Gut Barrier and Its Importance in Establishing Immunity in Newborn Mammals

“…The cytokine profile of breast milk changes during the lactation period with differences in relative cytokine content in colostrum, transition milk and mature milk and, in addition, breast milk composition is also adapted to the delivery period, being different in term, preterm and very preterm neonates (104). Some of these bioactive factors, such as the EGF, have a low intestinal absorption ratio and they function mainly in the development of the gut and mucosal immune system, while others such as IL-2, are mostly absorbed and by entering the systemic circulation they can influence the maturing immune system (105).…”

The Role of Human Milk Oligosaccharides and Probiotics on the Neonatal Microbiome and Risk of Necrotizing Enterocolitis: A Narrative Review

“…Breast milk from mothers of preterm infants contains a multitude of immunomodulating components, including soluble immunoglobulin A (IgA), growth factors, and prebiotics. These factors have known protective mechanisms against intestinal dysbiosis, intestinal barrier dysfunction, and risk of NEC [ 13 ]. The benefits of breast milk on the intestine were demonstrated using an ex vivo culture of neonatal mouse and premature human derived enteroids, in which exposure to human breast milk increased growth and proliferation of the enteroids [ 14 ].…”

Effect of Different Milk Diet on the Level of Fecal Calprotectin in Very Preterm Infants

“…It is a challenge to explain why FC levels are higher in breastfed infants than formula-fed ones since FC is an index of bowel inflammation. On the contrary, it is evident that human milk contains several anti-inflammatory bioactive components that promote intestinal growth and maturation and reduce intestinal permeability more than formulas ( 22 – 25 ). It has been hypothesized that higher FC in breastfed neonates could be consistent with the promotion of maturation of the intestinal mucosa.…”