Dietary nucleotides in infant formula affect fecal bacterial composition.

Nucleotides are non protein nitrogen compounds suggested to be important for the development and maturity  of the infant's gastrointestinal tract and also for immunity. They are found in larger amounts in breast milk than infant formula and are often said to be one of the reasons why breast fed infants experience fewer infections, less diarrhoea and gastroenterities than those  fed formula .

Nucleotides are now added to some infant formulas. A study in the UK was undertaken to investigate the effects of nucleotide containing infant formulas on the fecal bacterial composition, incidence of diarrhoea and stool characteristics  of formula fed infants from birth to 5 months of age. Infants fed nucleotide supplemented infant formula (100), non supplemented infant formula (100) and breast milk(101) were compared. 88 using the nucleotide  supplemented formula, 86 using the non supplemented formula and 96 breast fed babies completed the trial. The study found that the nucleotide supplemented formula group had similar levels of Bifidobacterium in their stools as  breast fed infants. Infants taking the unsupplemented formula had lower levels of Bifidobacterium in their stools. This indicates that the nucleotides had a prebiotic effect , increasing the numbers of Bifidobacterium in the large intestine similar to those breast fed, which could protect the infant from infections. The stools of the supplemented formula group were softer than the non supplemented at 8 weeks but not at 16 weeks or 20 weeks and stool frequency did not differ. Breast fed infants had fewer diarrheal episodes, softer stools and greater stool frequency than the formula groups.  The study supports the prebiotic effect of nucleotides in the large intestine and suggests they are important for optimizing the diet of formula fed infants.

Reference

Singhal A, Macfarlane G, Macfarlane S et al. Dietary nucleotides and fecal microbiota in formula-fed infants: a randomized controlled trial. Am J Clin Nutr 2008;87:1785-92