Gastrointestinal Tolerance, Growth and Safety of a Partly Fermented Formula with Specific Prebiotics in Healthy Infants: A Double-Blind, Randomized, Controlled Trial

This study evaluated the effect of a partly fermented infant formula (using the bacterial strains Bifidobacterium breve C50 and Streptococcus thermophilus 065) with a specific prebiotic mixture (short-chain galacto-oligosaccharides (scGOS) and long-chain fructo-oligosaccharides (lcFOS; 9:1)) on the incidence of gastrointestinal symptoms, stool characteristics, sleeping and crying behaviour, growth adequacy and safety. Two-hundred infants ≤28 days of age were assigned either to experimental infant formula containing 30% fermented formula and 0.8 g/100 mL scGOS/lcFOS or to non-fermented control infant formula without scGOS/lcFOS. A group of breastfed infants served as a reference. No relevant differences in parent-reported gastrointestinal symptoms were observed. Stool consistency was softer in the experimental versus control group with values closer to the breastfed reference group. Daily weight gain was equivalent for both formula groups (0.5 SD margins) with growth outcomes close to breastfed infants. No clinically relevant differences in adverse events were observed, apart from a lower investigator-reported prevalence of infantile colic in the experimental versus control group (1.1% vs. 8.7%; p < 0.02). Both study formulae are well-tolerated, support an adequate infant growth and are safe for use in healthy term infants. Compared to the control formula, the partly fermented formula with prebiotics induces stool consistencies closer to breastfed infants.