Effects of Prebiotic‐Containing Infant Formula on Gastrointestinal Tolerance and Fecal Microbiota in a Randomized Controlled Trial

Background : Prebiotic‐containing infant formula may beneficially affect gastrointestinal tolerance and commensal microbiota composition. Objective : Assess gastrointestinal tolerance and fecal microbiota, pH, and short‐chain fatty acid (SCFA) concentrations of infants consuming formula with or without prebiotics. Design : Full‐term formula‐fed infants were studied to a breastfed comparison group (BF). Formula‐fed infants (FF) were randomized to consume a partially hydrolyzed whey formula with (PRE) or without (CON) 4 g/L of galacto‐oligosaccharides and fructo‐oligosaccharides (9:1). Fecal bacteria, pH, and SCFA were assessed at baseline, 3 weeks, and 6 weeks. Caregivers of patients recorded stool characteristics and behavior for 2 days before the 3‐ and 6‐week visits. Results : Feces from infants fed PRE had a higher absolute number ( P = .0083) and proportion ( P = .0219) of bifidobacteria than CON‐fed infants and did not differ from BF. BF had a higher proportion of bifidobacteria than CON ( P = .0219) and lower number of Clostridium difficile than FF ( P = .0087). Feces from formula‐fed infants had higher concentrations of acetate ( P < .001), butyrate ( P < .001), propionate ( P < .001), and total SCFAs ( P = .0230) than BF; however, fecal pH was lower ( P = .0161) in PRE and BF than CON. Prebiotic supplementation did not alter stool patterns, tolerance, or growth. BF had more frequent stools that were yellow ( P < .0001) and more often liquid than FF ( P < .0001). Conclusions : Infant formula containing the studied oligosaccharides was well tolerated, increased abundance and proportion of bifidobacteria, and reduced fecal pH in healthy infants.