Specific Antibodies in Breastmilk required to Prevent Necrotizing Enterocolitis in Premature Babies
Necrotizing Enterocolitis (NEC) is a serious condition particularly affecting premature babies where the where tissue in the bowel (small and large intestines) becomes inflamed. NEC can make a baby temporarily unable to take milk, and at its worst it can cause parts of the bowel to become so damaged that tissue within it dies.
"Necrotizing" means damage and death of cells
"Entero" refers to the intestine
"Colitis" means inflammation of the colon (lower part of the intestine)
NEC is most common in babies weighing less than 4lb and affects up to 5% of babies in newborn intensive care units. Although it may develop in any newborn, most cases occur in premature babies.
In NEC it is thought that the intestinal tissues are weakened by too little oxygen or blood flow and is associated with the start of feeding. When feedings are started and the food moves into the weakened area of the intestinal tract, bacteria from the food can damage the intestinal tissues. The tissues may be severely damaged and die, which can cause a hole to develop in the intestine. This can lead to severe infection in the abdomen. Just a small part of the bowel or the whole bowel can be affected leading to some babies needing to have some of their bowel removed through surgery. Unfortunately some babies will die.
This latest research shows that breastmilk contain critical factors for the prevention of NEC.
It has long been known that the incidence of NEC is substantially lower in infants fed with breastmilk, although the mechanisms that underlie this benefit were not clear.
NEC is associated with decreased diversity and increased numbers of Enterobacteriaceae in the intestinal microbiota; this research shows that maternal immunoglobulin A (IgA) - an antibody, protects against NEC and that the primary source in early life of IgA's is breastmilk.
A dedicated analysis of samples from a single formula-fed preterm infant revealed no IgA bacteria in the first 4 weeks of life, strongly indicating that maternal milk was the primary source of perinatal IgA.
"samples from maternal-milk-fed infants contained a far greater abundance of IgA-bound (IgA+) bacteria compared to formula-fed infants".
" (11 out of 19) of formula-fed infants had less than 1% of their intestinal bacteria bound by IgA, .. Indeed, we found a significant temporal relationship between age and IgA binding in formula-fed infants that was not observed among maternal-milk-fed infant surveyed across all samples"
Furthermore, researchers confirmed that IgA is critical for preventing NEC in a mouse model. Pups that were reared by IgA-deficient mothers were susceptible to disease despite exposure to maternal milk. These findings show that maternal IgA shapes the host–microbiota relationship of preterm neonates and that IgA in maternal milk is a critical and necessary factor for the prevention of NEC.
Access article here: https://www.nature.com/articles/s41591-019-0480-9.epdf