Those of you being in-serviced by formula reps claiming the wonders of a new ingredient in advanced formula may be interested in preparing to respond to this hype. The rep is probably going to give you a speech on the addition of nucleotides to their formula. This was done in Canada first where it was claimed that this offered some measure of disease protection. The rival formula company challenged this claim and it had to be removed from the advertising. Here in the US, this formula is advertised as having a new ingredient that promotes the well being of cell membranes which brings the formula closer in composition to breast milk. Nucleotides are thought to be one class of the many modulators of the immune system. They are responsible, among other things, for increased bifidobacteria (the good kind) and a reduction in gut pathogens (the bad kind) in the intestines of breastfed babies. The formula company picked a few of the more abundant nucleotides in breast milk and added them to their formula, claiming it is now the closest to breastmilk. Several studies have shown that the addition of these nucleotides to formula actually cause the opposite of what they were intended to do. They demonstrated increased E coli counts, decreased bifidobacteria, and increased counts of bacteroids compared to the fecal flora of breastfed babies. This serves as another example of parental feeding decisions dictated by marketing practices. Quan R, Barness LA, Uauy R: Do infants need nucleotide supplemented formula for optimal nutrition? Journal of Pediatric Gastroenterology and Nutrition 1990; 11:429-437 Carver JD, Pimentel B, Cox WI, Barness LA: Dietary nucleotide effects upon immune function in infants. Pediatrics 1991; 88:359-363 Balmer SE, Hanvey LS, Wharton BA: Diet and faecal flora in the newborn: nucleotides. Archives of Disease in Childhood 1994; 70:F137-F140