Effects on faecal microbiota of dietary and acidic oligosaccharides in children during partial formula feeding.

Objective: To test the safety and effect on faecal microbiota of a formula with prebiotic oligosaccharides alone or in combination with acidic oligosaccharides in infants at the age of partial formula feeding. Patients and Methods: The study was a double-blind, placebo-controlled, randomised intervention trial in which 82 healthy, full-term, partially breast-fed children, from 1 week to 3 months old, were given 1 of the following formulae: whey-based formula (control group), whey-based formula with galacto- and long-chain fructo-oligosaccharides (scGOS/lcFOS group), or whey-based formula with galactoand long-chain fructo-oligosaccharides added with pectinderived acidic oligosaccharides (scGOS/lcFOS/ pAOS group). Children were studied for the duration of the partial formula feeding period and every 2 weeks for 2 months after breast-feeding cessation. The total bacteria count and the proportion of 7 bacterial families were determined using in situ hybridisation coupled to flow cytometry. Results: The total bacterial count did not alter with time or type offeeding(9.9 � 0.1log 10 cellspergramwetweight).Compared with the control group, there was an increase of the Bifidobacterium genus ( P ¼0.0001), and a decrease of proportions for the Bacteroides group ( P ¼0.02) and the Clostridium coccoides group ( P ¼0.01) in both oligosaccharide groups. The proportion of bifidobacteria was significantly higher in the scGOS/lcFOS/pAOS compared with the scGOS/lcFOS group (P<0.01). Conclusions: Infant formulae appear to be clinically safe and effective on infant microbiota. They minimize the alteration of faecal microbiota after cessation of breast-feeding and promote bifidobacteria proportions, with a stronger effect when acidic oligosaccharides are present. JPGN 46:580–588, 2008.