Objectives : Infant formulas typically lack prebiotic human milk oligosaccharides (HMO) that promote the growth of beneficial gut flora. Supplementation of infant formulas with a variety of non-HMO prebiotics has attempted to replicate this effect, but study sizes have been small and results have been inconclusive. This meta-analysis summarized the results of the published studies of Bifidobacteria abundance in infants fed standard and non-HMO prebiotic-supplemented formulas compared to that of exclusively breastfed infants.
Methods : A literature search was conducted of PubMed and EMBASE for randomized controlled trials of Bifidobacteria abundance in healthy, term, pre-weaning human infants given a non-HMO prebiotic-supplemented infant formula (PF) or a control formula (CF) compared to an exclusively breastfed (EBF) reference group. The prebiotics tested were fructo-oligosaccharide (FOS), galacto-oligosaccharide (GOS), polydextrose (PDX), and inulin; CF were identical to corresponding PF excepting the addition of prebiotics. Results were pooled and post-intervention standardized mean difference in Bifidobacteria absolute abundance was calculated for CF and PF groups compared to an EBF reference group and to each group’s own baseline value. Network meta-analysis summarized the data for each group. Significance was set at p< 0.05.
Results : Nine studies representing 12 test formulas met inclusion criteria. No significant differences were found between CF, PF, and EBF post-treatment or from baseline; however, trends were observed toward lower absolute abundance in the post-treatment CF group compared to EBF (p=0.063) and increased abundance in both the EBF (p=0.074) and PF (p=0.073) groups from baseline.
Conclusions : Our meta-analysis identified 12 eligible trials of non-HMO prebiotics. Trends were observed toward lower Bifidobacteria abundance in CF groups post-intervention and increases from baseline in the EBF and PF groups, but we failed to find significant post-intervention differences among CF, PF and EBF groups. We conclude that current evidence does not provide definitive support for use of non-HMO prebiotics to increase infant colonization with Bifidobacteria.
Funding Sources : The University of Cincinnati College of Medicine, Department of Environmental Health