This study investigated growth, safety, and tolerance in healthy infants consuming a partly fermented infant formula (IF) with postbiotics, 2'-linked fucosyllactose (2'-FL), a specific prebiotic mixture of short-chain galacto-oligosaccharides (scGOS) and long-chain fructo-oligosaccharides (lcFOS), and milk fat. This double-blind, controlled trial randomised 215 fully IF-fed infants ≤ 14 days of age to either: Test Group (IF) containing 26% fermented formula with postbiotics derived from Lactofidus fermentation process (including 3'-Galactosyllactose; 3'-GL), 0.8 g/100 mL scGOS/lcFOS (9:1), 0.1 g/100 mL 2'-FL, and milk fat), or Control group (IF with 0.8 g/100 mL scGOS/lcFOS (9:1)) until 17 weeks of age. Fully breastfed infants were included as a reference. Anthropometric measures, gastrointestinal symptoms, and safety were assessed monthly. Equivalence in weight gain (primary outcome) between the Test and Control groups was confirmed (difference in means -0.08 g/day; 90% CI (-1.47;1.31)) with estimated mean weight gain (SE) of 31.00 (0.59) g/day and 31.08 (0.60) g/day, respectively, (PP population, n = 196). Equivalence in length and head circumference gain between the randomised groups was also confirmed. No statistically significant differences were observed in adverse events or gastrointestinal tolerance between randomised IF groups. A partly fermented IF with postbiotics, specific oligosaccharides, 2'-FL, and milk fat supports adequate infant growth and is safe and well-tolerated in healthy term infants.
Keywords: 2′-linked fucosyllactose (2′-FL); 3-galactosyllactose (3′-GL); infant growth; postbiotic; prebiotic; safety; tolerance.