Secretory antibodies in breast milk promote long-term intestinal homeostasis by regulating the gut microbiota and host gene expression

Abstract

Significance An experimental system was developed in mice to study the long-term benefits of early exposure to secretory antibodies of the IgA class (SIgA) in breast milk. We found that breast milk-derived SIgA promoted intestinal epithelial barrier function in suckling neonates, preventing systemic infection by potential pathogens. Long-term benefits of early exposure to SIgA included maintenance of a healthy gut microbiota and regulation of gene expression in intestinal epithelial cells. These findings suggest that maternal antibodies provide benefits to the intestinal immune system of the breast-fed infant, which persist into adulthood.

Homage to the ‘H’ in developmental origins of health and disease

“…As indicated above, breast milk induces long-term offspring gut microbiome changes that can have dramatic health consequences. 89,90 In adult rodents, exercise changes the gut microbial populations. [140][141][142][143] In turn, the composition of the gut microbiota may influence exercise performance of mice through anti-oxidant enzyme production.…”

Breast milk, microbiota, and intestinal immune homeostasis

“…This observation is most apparent at birth with the first time exposure to oral feedings. Furthermore, several recent publications suggest that breastfeeding protection is primarily mediated through bacterial colonization (59). Since newborn intestinal microbiota is in a formative stage of development, modifications may have an important and timely impact on development of intestinal immune function.…”

“…These factors also contribute to the composition of luminal and enterocyte surface bacteria. For example, a decrease in pIgA levels in breast milk has been shown to result in a different intestinal microbiota than with adequate pIgA levels (59,76). This difference in bacterial composition has also been shown after reduction in soluble components of the innate immune response (77).…”

Re-thinking the functions of IgA+plasma cells

“…24 This is also the case for IgA that is ingested through breast milk, and such effects of IgA on the luminal side of the gut can have a long-term impact on intestinal homeostasis beyond infancy. 83 Furthermore, mice lacking B cells, IgA or the pIgR exhibit changes in the intestinal microbial ecology and increased serum titers of antibodies specific for commensal and food antigens. [84][85][86][87][88][89][90][91] Bacteria in turn adapt to IgA by altering their gene expression patterns, 92 demonstrating the critical role for IgA in regulating host-microbial mutualism.…”