Objectives: Levels of stool fatty acid soaps and beneficial bacteria differ between formula-fed and breast-fed infants; addition of specific formula ingredients may reduce these differences. This study evaluated the effects of a term infant formula containing high sn-2 palmitate (sn-2) or an identical formula supplemented with oligofructose (OF) at two concentrations on stool composition, stool characteristics, and fecal bifidobacteria.
Methods: Healthy, term formula-fed infants 7-14 days old (n = 300) were randomized in a double-blind manner to receive standard formula (Control), sn-2, sn-2+3 g/L OF, or sn-2+5 g/L OF for 8 weeks. Human milk (HM)-fed infants (n = 75) were studied in parallel. Stool samples were collected from all subjects at week 8 for fatty-acid soaps and mineral content, and from a subset at baseline and week 8 for bifidobacteria. Stool characteristics were assessed via 3-day diary.
Results: The sn-2 group had 46% less stool soap palmitate (P < 0.001) and softer stools than Control (20% more mushy soft stools, P = 0.026; 50% fewer formed stools, P = 0.003). Addition of OF resulted in even fewer formed stools versus Control (65% fewer for sn-2+3 g/L OF; 79% fewer for sn-2+5 g/L OF), with 5 g/L OF more closely resembling that of HM-fed infants. Both sn-2 (P < 0.05) and sn-2 with OF groups (P < 0.01) had significantly higher fecal bifidobacteria concentrations than Control at week 8, not differing from HM-fed infants.
Conclusions: High sn-2-palmitate formulas led to reduced stool soaps, softer stools, and increased bifidobacteria, while addition of OF further improved stool consistency. Those modifications brought outcomes in formula-fed infants closer to that in HM-fed infants.
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(C) 2014 by European Society for Pediatric Gastroenterology, Hepatology, and Nutrition and North American Society for Pediatric Gastroenterology,