A complex infection pg. 3
Many breast milk components have been studied, including epidermal growth factor (EGF). Investigators know there is a role of EGF in NEC. Mice that are deficient in the EGF receptor will develop intestinal necrosis similar to the human disorder.
“EGF promotes bowel healing by increasing the replication and migration of epithelial cells,” McElroy explains. “However, expression of EGF receptor is lower in premature infants compared to adults. EGF is important in preventing NEC, and premature infants have lower levels of the major receptor of EGF than adults.
“This coupled with the fact that TNF causes a disruption of normal EGF receptor signaling may be one of the reasons they are more susceptible to the disease,” he continues. “That is why our lab focuses on the roles that TNF, EGF and their receptors play in the mechanisms of gastrointestinal injury and repair during development.”
Some studies outside the United States show that probiotics (helpful bacteria) decrease the incidence of NEC in premature babies. The first study of this kind was done in Colombia, South America, where babies were given a combination of two probiotics.
“They were able to demonstrate an almost 50 percent decrease in the incidence of NEC from the year prior to the year it was being used,” says Mario A. Rojas, M.D., associate professor of Pediatrics at Vanderbilt.
These findings stimulated similar research in other countries, but there are very few under way in the United States thus far, in part due to the fact that probiotics are currently sold as nutritional supplements.
To receive federal funds to study probiotics in a specific disease, the U.S. Food and Drug Administration requires that the investigator submit an investigational new drug application, which can delay and increase the expense of the study.
“I’ve been trying to do research with this ever since this study came out in the 1990s,” Rojas says. “We feel there is enough biomolecular and clinical data to support a well-designed multicenter trial, but funding has been very difficult to obtain in the U.S.”
So Rojas has turned his attention to probiotic studies outside of the United States. He has currently enrolled 250 patients in a double-blinded randomized controlled trial in nine medical centers in his native Colombia. The focus of the study is a probiotic called Lactobacillus reuteri, which has been shown to be effective in the treatment of babies with colic.
The gastrointestinal (GI) tracts of babies admitted to the intensive care nursery are colonized by Gram-negative (pathogenic) bacteria very quickly. Premature babies have immature GI tracts that allow pathogens to move from the mucosa into the bowel wall, where they produce inflammation and damage, and then into the bloodstream. The result is sepsis, an overwhelming, body-wide infection that is life-threatening.