Probiotics and prebiotics in preterm infants: where are we? Where are we going?

Background: Uncertainty exists regarding the efficacy and safety of using probiotics and prebiotics in preterm infants.

Aim: To review the evidence on the effects of administering probiotics and/or prebiotics to preterm infants.

Methods: MEDLINE and the Cochrane Library were searched in August 2008. A supplemental search was conducted in July 2009. Only systematic reviews/meta-analyses and randomized controlled trials (RCTs) that evaluated the effects of probiotics and/or prebiotics on relevant short- and long-term primarily clinically important health outcomes published in the English language were included.

Results: One systematic review and 2 well-performed meta-analyses suggest that probiotics reduce the risk of necrotizing enterocolitis (NEC) (stage > or =2). One subsequently published RCT reported similar results. The 2 meta-analyses also demonstrated that probiotics reduce the risk of death due to all causes, but do not have an effect on the risk of sepsis or death due to NEC. Regarding prebiotics, one meta-analysis of 4 RCTs demonstrated that prebiotic-supplemented formula increases stool colony counts of bifidobacteria and lactobacilli in preterm neonates without adversely affecting weight gain. Because of the limited data regarding synbiotics, the relationship between their use and clinical outcomes in preterm infants remains unclear.

Conclusions: The findings from the 2 meta-analyses of the effects of probiotic administration on the prevention of NEC show potential for such dietary supplementation. However, they must be interpreted with caution because the beneficial effects of probiotics seem to be strain specific, thus, pooling data from different strains may result in misleading conclusions. Before the routine use of probiotics and/or prebiotics in preterm infants, data regarding which products should be administered, at what dose, and for how long are needed.