Effects of Bovine α‐Lactalbumin and Casein Glycomacropeptide–enriched Infant Formulae on Faecal Microbiota in Healthy Term Infants

Objective: Certain milk factors may promote the growth of a host‐friendly gastrointestinal microbiota, for example, one that is predominated by bifidobacteria, a perceived health‐promoting genus. This may explain why breast‐fed infants experience fewer intestinal infections than their formula‐fed counterparts who are believed to have a more diverse microbiota, which is similar to that of adults. The effects of formulas supplemented with 2 such ingredients from bovine milk, α‐lactalbumin (α‐lac) and casein glycomacropeptide (GMP), on gut flora were investigated in this study. Patients and Methods: Six‐week‐old (4–8 wk), healthy term infants were randomised to a standard infant formula or 1 of 2 test formulae enriched in α‐lac with higher or lower GMP until 6 months. Faecal bacteriology was determined by the culture‐independent procedure fluorescence in situ hybridisation. Results: There was a large fluctuation of bacterial counts within groups with no statistically significant differences between groups. Although all groups showed a predominance of bifidobacteria, breast‐fed infants had a small temporary increase in counts. Other bacterial levels varied in formula‐fed groups, which overall showed an adult‐like faecal microflora. Conclusions: It can be speculated that a prebiotic effect for α‐lac and GMP is achieved only with low starting populations of beneficial microbiota (eg, infants not initially breast‐fed.