Effect of iron on neonatal gut flora during the first three months of life

To study the effect of milk supplemented with iron on neonatal gut flora, faecal specimens of ten infants receiving breast milk, six receiving a cow-milk preparation supplemented with iron (5 mg/l) and seven receiving the same product without iron supplement (iron concentration <0.5 mg/l) were examined during the first 12 weeks of life. In breast-fed infants bifidobacteria was predominant, counts ofEscherichia coli were low, and other bacteria were rarely present. Infants receiving fortified cow-milk preparation had high counts ofEscherichia coli, counts and isolation frequency of bifidobacteria were low and other bacteria were frequently isolated. In those on unfortified cow-milk preparation isolation frequency ofEscherichia coli, bifidobacteria and bacteroides was comparable with that in breast-fed infants; however, counts ofEscherichia coli were high. It is concluded that the faecal flora of infants fed unfortified cow-milk preparation acquires characteristics of that found in breast-fed infants.