Probiotic supplements for preterm infants

There are now a number of trials demonstrating that live bacteria, similar to those found in human milk (probiotics), may decrease the incidence of necrotizing enterocolitis when fed to very preterm infants. There are no studies of the physiologic effects of these organisms on gut function. In this issue of The Journal, Indrio et al report their measurements of clinical symptoms and gastric electrical activity and emptying in infants at about 34 weeks gestation. Infants were randomized to formula or formula plus lactobacillus for 30 days and compared with infants fed with human milk. There were no differences in growth or major adverse events. The infants that received lactobacillus had less regurgitation, less crying, and more stools than the formula-fed infants. Gastric emptying also was faster with lactobacillus supplementation. Some of the measurements for the lactobacillus supplementation also differed from the infants fed with human milk. These results suggest physiologic differences in GI function with lactobacillus supplementation. The relationship between these effects and a decrease in necrotizing enterocolitis in much more preterm infants is unclear. This field of research is plagued by poorly characterized probiotic supplements that are not consistently available. Ultimately, any routine clinical use must await information about which probiotic organisms should be given, at which dose, and for how long.