Dietary nucleotides and fecal microbiota in formula-fed infants: a randomized controlled trial.
BACKGROUND
Dietary nucleotides are nonprotein nitrogenous compounds that are thought to be important for growth, repair, and differentiation of the gastrointestinal tract. A higher nucleotide intake may also have favorable effects on the fecal microbial composition and incidence of diarrhea in infancy. However, few studies have tested this hypothesis with an experimental study design.


OBJECTIVE
We tested the hypothesis that nucleotide supplementation of infant formula has beneficial effects on fecal bacteriology.


METHODS
Oligonucleotide probes were used to measure bacterial genus-specific 16S ribosomal RNA in stools of a subset of infants (mean age: 20.4 wk) who were randomly assigned to nucleotide-supplemented (31 mg/L; n = 35) or control formula (n = 37) from birth until age 20 wk or were breastfed (reference group; n = 44). The microbial pattern was assessed as the ratio of Bacteroides-Porphyromonas-Prevotella group (BPP) to Bifidobacterium species.


RESULTS
The ratio of BPP to Bifidobacterium spp. rRNA in infants randomly assigned to the nucleotide-supplemented formula was lower than in infants receiving the control formula (mean difference: -118%; 95% CI: -203%, -34%; P = 0.007), but it did not differ in infants who were breastfed. The difference between randomized formula-fed groups was independent of potential confounding factors (P = 0.003).


CONCLUSIONS
Our data support the hypothesis that nucleotide supplementation improves the composition of the gut microbiota in formula-fed infants. Because this effect could contribute to previously described benefits of nucleotide supplementation for gastrointestinal tract and immune function, these findings have important implications for optimizing the diet of formula-fed infants.
Childhood Nutrition Research Center, Institute of Child Health, London, United Kingdom. a.singhal@ich.ucl.ac.uk
Atul
A
Singhal
George
G
Macfarlane
Sandra
S
Macfarlane
Julie
J
Lanigan
Kathy
K
Kennedy
Alun
A
Elias-Jones
Terence
T
Stephenson
Peter
P
Dudek
Alan
A
Lucas
D001644:Bifidobacterium / Q000302:isolation & purification; D001724:Birth Weight; D001942:Breast Feeding; D003967:Diarrhea / Q000453:epidemiology; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins; D019587:Dietary Supplements; D002149:Energy Intake; D005243:Feces / Q000382:microbiology*; D005260:Female; D041981:Gastrointestinal Tract / Q000382:microbiology; D006801:Humans; D007223:Infant; D041943:Infant Formula; D008297:Male; D009711:Nucleotides / Q000008:administration & dosage*; D012923:Social Class
D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins; D009711:Nucleotides