OBJECTIVETo study the effect of a low level of galacto-oligosaccharides (GOS) on intestinal bifidobacteria and lactobacilli, and fermentation characteristics in term infants by comparing with human milk and a standard infant formula without GOS.

METHODSA total of 371 term infants from four hospitals of China were enrolled. The infants started with breast feeding. After 1-2 weeks, some of the infants were changed to feeding with formula milk and then were randomly assigned to two formula-feeding groups: with or without GOS supplementation (2.4 g/L). Growth, stool characteristics, and side effects were recorded in a 3-month-follow-up. Faecal samples were collected for analysis of intestinal bacteria (culture technique), acetic acid (gas chromatography) and pH (indicator strip) at postnatal 3 months.

RESULTSCompared with the formula-feeding group without GOS, the contents of bifidobacteria, lactobacilli and acetic acid and stool frequency increased, and faecal pH decreased significantly in the GOS-formula-feeding and the human milk group. There were no significant differences between the GOS-formula-feeding and the human milk groups. Supplementation with GOS did not lead to an increase in the incidence of crying, regurgitation and vomiting.

CONCLUSIONSA supplementation of low levels of GOS in infant formula seemed to improve stool frequency, decrease faecal pH, and stimulate intestinal bifidobacteria and lactobacilli up to levels as found in breast-fed infants.