A new study finds another potential benefit in breast milk for prematurely born infants: protection from a dangerous infection.
New research finds babies are less likely to develop the intestinal disease necrotizing enterocolitis (NEC) if they have breast milk’s immunoglobulin A (IgA) antibodies in them.
This is according to a new study published in the journal
The researchers found that because IgA antibodies bind to bacteria that are responsible for the disease, infants with the antibody have a better chance at avoiding NEC.
The news is particularly important for parents of infants born prematurely, who are more likely to have NEC.
Researchers say these new findings may help protect infants and encourage physicians to help parents of premature infants get access to breast milk even if they can’t produce it themselves.
Medical professionals already knew that babies with NEC have Enterobacteriaceae bacteria in them. They also knew that breast milk can help protect infants from the disease.
Now researchers say these findings about IgA offer new hope in preventing and treating the dangerous infection.
NEC is a rare disease that occurs in about 1 to 3 of every 1,000 live births. It’s commonly seen by clinicians in advanced neonatal intensive care units (NICUs).
More than 90 percent of NEC cases occur in infants born before 32 weeks who have extremely low birth weights under 3.3 pounds. Full-term infants can get NEC, but only about 10 percent of them develop it.
Infants with NEC experience acute and chronic intestinal inflammation. Their microbiome, immature intestinal system, immune response, and pathogen exposure can lead to sepsis and multi-organ failure.
Risk factors for NEC include:
- abnormal bacterial colonization of the bowel
- increased release of inflammatory mediators
- intestinal ischemia-reperfusion injury
- use of acid-reducing medications
- transfusion-associated gut injury
- hypoxia, or low levels of oxygen in body tissues
- being fed formula
The standard treatment for NEC is antibiotics.
The intestines of preterm infants are developed structurally but they’re functionally immature and weaker compared to that of an infant born at full-term.
The preterm baby’s gut immune system isn’t fully formed and their host defenses aren’t able to fight like full-term infants’ intestines can, explained Dr. Misty Good, an assistant professor of pediatric pathology and immunology at the Washington University School of Medicine.
Timothy Hand, PhD, senior author and an assistant professor of pediatric infectious diseases at the R.K. Mellon Institute for Pediatric Research and Pitt’s School of Medicine, evaluated fecal samples from 30 preterm infants with NEC and 39 infants of the same age who didn’t have NEC.
Experts still aren’t sure what causes NEC. Bacterial invasion is part of it, but something else occurs prior to its development that’s still not understood, Hand said.
During the study, babies on breast milk had more IgA-bound gut bacteria than those on formula. Those who developed NEC were more likely to have been given formula.
Over time, children who had IgA had more diverse flora and a healthier gut.
The researchers also bred mice that couldn’t produce IgA in their breast milk. At birth, mice have an intestinal development comparable to a human baby born at 24 weeks. Those on IgA-free milk were just as susceptible to NEC as those on formula.
Breastfeeding alone isn’t enough to prevent NEC — the milk has to contain IgA, Hand noted.
Hand was most surprised to find that there was a consistent and abrupt loss of antibody binding on intestinal bacteria before the disease develops.
“We believe that the bacteria may be evolving to escape antibodies in the maternal milk, but they might also just proliferate too fast and the antibody in the maternal milk is overwhelmed,” Hand said, regarding these cases where the disease develops. “When the bacteria are free from antibodies, we suspect they are better able to invade the host.”
Experts don’t want to make already stressed parents more anxious with the new research findings. When some parents can’t breastfeed or choose not to, there are other options.
In cases where breastfeeding or providing pumped milk isn’t an option, donor milk is a possible solution for new parents.
“A woman should never feel unnecessary pressure about her choice in regards to her infant’s diet,” Hand said. “However, mothers of preterm infants should know that formula feeding carries an increased risk of NEC.”
In some cases donor milk has been linked to slower growth rates in preterm infants. While formula may be easier to give to infants, it’s been linked to a substantial increase in the incidence of NEC.
Parents can make the decision that works for them and their infant after consulting with their doctor.
“IgA is necessary but may not be sufficient to prevent NEC,” Hand said. “What we’re arguing is that you might want to test the antibody content of donor milk and then target the most protective milk to the most at-risk infants.”
Another issue is that preterm infants can’t breastfeed until they’re developmentally ready, usually around 34 weeks, Good noted. They’re fed through a tube until then and they can be given either pumped breast milk or formula.
Parents who deliver early and want to try to give their preterm infant breast milk should begin pumping soon after delivery. Pumping every three hours can increase supply.
But not all moms can produce breast milk if their baby is born prematurely — and it’s not their fault if they can’t produce it, Good said.
She recommends moms utilize lactation consultants, NICU nurses, and neonatologists for support.
“Breast milk is important for a premature baby, especially the early colostrum, so mothers should try to save every drop,” Good said. “It may be hard especially in the beginning for the milk to come in since the baby delivered premature, but breast milk is like medicine to them and it’s the most important thing a mother can provide her infant that the NICU can’t.”
Sheila Gephart, PhD, RN, the principal investigator for the NEC-Zero Project, said most parents never hear about NEC until their baby has it. At that time, they’re less likely to absorb critical information because they’re in crisis mode.
“Doctors say they’re afraid to tell parents about NEC because they don’t want to overwhelm or scare them, but parents have the most to lose if their baby gets NEC and they want to know the risks and the warning signs,” Dr. Gephart told Healthline.
“Sharing information empowers parents. For babies born early, mothers need to be informed about the value of breast milk as medicine — a life-saving treatment — that they’re best suited to provide,” she said.
Gephart added that pumping within the first hour of birth has been shown to make women more likely to sustain their milk supply during the critical periods when an infant is most at risk for NEC.
Dr. Gail Besner, principal investigator in the Center for Perinatal Research in The Research Institute at Nationwide Children’s Hospital, said more needs to be done to help prevent NEC.
“You can do everything right and NEC can still develop. We need advanced strategies for prevention and treatment if we are to eliminate NEC from the NICU,” she continued.