The Effect of Breastfeeding on Childhood Otitis Media

Mucosal immunity reduces the need for elimination of penetrating exogenous antigens by proinflammatory systemic immunity. The adult gut mucosa contains some 80% of the body's activated B cells-differentiated to plasmablasts and plasma cells (PCs). Most mucosal PCs produce dimeric immunoglobulin A (IgA), which, along with pentameric immunoglobulin M (IgM), can be exported by secretory epithelia expressing the polymeric immunoglobulin receptor. Immune exclusion of antigens is performed mainly by secretory IgA in cooperation with innate defenses, but, in newborns and in IgA deficiency, secretory IgM is important. In the gut, induction and regulation of mucosal immunity occurs primarily in gut-associated lymphoid tissue-particularly the Peyer's patches-and also in mesenteric lymph nodes. Terminal differentiation to PCs is accomplished in the lamina propria to which the activated memory/effector T and B cells home. Lactating mammary glands are part of the secretory immune system, and IgA antibodies in breast milk reflect antigenic stimulation of gut-associated lymphoid tissue and nasopharynx-associated lymphoid tissue such as the tonsils. Breast-milk antibodies are thus highly targeted against infectious agents and other exogenous antigens in the mother's environment, which are those likely to be encountered by the infant. Therefore breast-feeding represents an ingenious immunologic integration of mother and child. Copyright 2010 Mosby, Inc. All rights reserved.

To synthesise the evidence on the association between duration and exclusivity of breastfeeding and the risk of acute otitis media (AOM).

Summary 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.