title: Molecular ecological analysis of fecal bacterial populations from term infants fed formula supplemented with selected blends of prebiotics.
abstract: Supplementation of infant formulas with prebiotic ingredients continues the effort to mimic functional properties of human milk. In this double-blind, controlled, 28-day study, healthy term infants received control formula (control group; n = 25) or control formula supplemented with polydextrose (PDX) and galactooligosaccharide (GOS) (4 g/liter) (PG4 group; n = 27) or with PDX, GOS, and lactulose (LOS) (either 4 g/liter [PGL4 group; n = 27] or 8 g/liter [PGL8 group; n = 25]). A parallel breast-fed group (BF group) (n = 30) was included. Stool characteristics, formula tolerance, and adverse events were monitored. Fecal bacterial subpopulations were evaluated by culture-based selective enumeration (Enterobacteriaceae), quantitative real-time PCR (Clostridium clusters I, XI, and XIV, Lactobacillus, and Bifidobacterium), and fluorescence in situ hybridization (FISH) (Bifidobacterium). Fecal bacterial community profiles were examined by using 16S rRNA gene PCR-denaturing gradient gel electrophoresis. The daily stool consistency was significantly softer or looser in the BF group than in all of the groups that received formula. The formulas were well tolerated, and the incidences of adverse events did not differ among feeding groups. Few significant changes in bacterial subpopulations were observed at any time point. The bacterial communities were stable; individual profiles tended to cluster by subject rather than by group. Post hoc analysis, however, demonstrated that the bacterial community profiles for subjects in the BF, PG4, PGL4, and PGL8 groups that first received formula at a younger age were less stable than the profiles for subjects in the same groups that received formula at an older age, but there was no difference for the control group. These data indicate that formulas containing PDX, GOS, and LOS blends are more likely to influence gut microbes when administration is begun in early infancy and justify further investigation of the age-related effects of these blends on fecal microbiota.
authors.affiliation: Division of Nutritional Sciences, Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1207 W. Gregory Drive, Urbana, IL 61801, USA. nnakamur@illinois.edu
authors.forename: Noriko
authors.initials: N
authors.lastname: Nakamura
authors.forename: H Rex
authors.initials: HR
authors.lastname: Gaskins
authors.forename: Chad T
authors.initials: CT
authors.lastname: Collier
authors.forename: Gerardo M
authors.initials: GM
authors.lastname: Nava
authors.forename: Deshanie
authors.initials: D
authors.lastname: Rai
authors.forename: Bryon
authors.initials: B
authors.lastname: Petschow
authors.forename: W Michael
authors.initials: WM
authors.lastname: Russell
authors.forename: Cheryl
authors.initials: C
authors.lastname: Harris
authors.forename: Roderick I
authors.initials: RI
authors.lastname: Mackie
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Wampler
authors.forename: D Carey
authors.initials: DC
authors.lastname: Walker
mesh_terms: D001419:Bacteria / Q000145:classification*; D015169:Colony Count, Microbial; D019587:Dietary Supplements / Q000009:adverse effects*; D004311:Double-Blind Method; D004586:Electrophoresis / Q000379:methods; D005243:Feces / Q000382:microbiology*; D041981:Gastrointestinal Tract / Q000502:physiology*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D041943:Infant Formula / Q000008:administration & dosage*; D007227:Infant Nutritional Physiological Phenomena; D007231:Infant, Newborn; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D012336:RNA, Ribosomal, 16S