Effects on Faecal Microbiota of Dietary and Acidic Oligosaccharides in Children During Partial Formula Feeding

ABSTRACT 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 galacto‐ and long‐chain fructo‐oligosaccharides added with pectin‐derived 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 of feeding (9.9 ± 0.1 log 10 cells per gram wet weight). Compared with the control group, there was an increase of the Bifidobacterium genus ( P = 0.0001), and a decrease of proportions for the Bacteroides group ( P = 0.02) and the Clostridium coccoides group ( P = 0.01) 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.