Acidic oligosaccharides from pectin hydrolysate as new component for infant formulae: Effect on intestinal flora, stool characteristics, and pH

Objectives: To come even closer to the functional composition of human milk, acidic oligosaccharides (AOS) from pectin were added to well known neutral prebiotics (galacto-oligosaceharides (GOS) and long-chain fructo-oligosaccharides (FOS)). The effect of AOS and GOS/FOS/AOS on intestinal flora, stool characteristics as well as acceptance and tolerance was investigated. Methods: Human milk contains 75% to 85% neutral and 15% to 25% acidic oligosaccharides. In this prospective, randomized, double blind study, a mixture of 80% neutral oligosaccharides (from long-chain galacto- and long-chain fructo-oligosaccharides) with 20% acidic oligosaccharides derived from pectin hydrolysis was investigated. Forty-six term infants were fed a standard formula supplemented with either maltodextrin as control (n = 15), or with 0.2 g acidic oligosaccharides (n = 16), or with the latter plus 0.6 g neutral oligosaccharides (mixture of galacto- and fructo-oligosaccharides; n = 15). Fecal flora using plating technique and pH were measured. Stool characteristics and possible side effects (crying, vomiting, and regurgitation) were recorded. Results: There was no difference in the bifidobacteria counts between the control and the group supplemented with acidic oligosaccharides alone (8.75 +/- 0.50 vs. 8.58 +/- 0.94 log colony forming units [CFU]/g stool). In infants fed the combination of acidic and neutral oligosaccharides, bifidobacteria were increased (9.61 +/- 0.70 log CFU/g stool; P < 0.01). The same pattern was observed with lactobacilli. Stool consistency was softest in infants fed the complete oligosaccharide mixture, but also in those fed formula supplemented with acidic oligosaccharides alone, the stool consistency was significantly softer compared with the control group. Fecal pH increased in the controls, remained constant in acidic oligosaccharides alone, and decreased in the complete mixture of oligosaccharides group. Conclusion: There was no difference in growth, crying, vomiting, and regurgitation patterns between the groups. In summary, acidic oligosaccharides from pectin hydrolysate are well tolerated as ingredient in infant formulae but do not affect intestinal microecology.