The Effect of "Humanised" Milks and Supplemented Breast Feeding on The Faecal Flora of Infants

SUMMARY Faecal specimens from 47 babies were examined each week during the first 6 weeks of life. Thirteen infants received breast milk alone, nine received Cow and Gate Premium milk, 10 received Scientific Milk Adaptation Gold Cap milk, and 15 received breast milk and in the first week of life a supplement of modified cows’ milk. An acetate buffer was demonstrated in the faeces of >60% of breast-fed infants during the first 4 weeks of life. No buffer was demonstrated in the faeces of either bottle-fed group over the same period. Only 20% of breast-fed infants receiving a supplement produced an acetate buffer in the 1st week, but this figure increased to 60% by the 4th week. Breast-fed babies produced faeces with a low pH (5.1–5.4), high counts of bifidobacteria and low counts of coliforms, bacteroides and clostridia; with the exception of acetic acid there was a notable absence of most volatile fatty acids from these faeces. Infants fed Premium milk produced faeces with a high pH (5.9-8.0) and a relatively high bifidobacterial count in the 1st week; thereafter no bacterial species predominanted. A wide variety of volatile fatty acids was present in these infants’ faeces. Infants fed Gold Cap milk produced faeces with a high pH (6.4–8.2) and a wide variety of volatile fatty acids; the counts of coliform bacilli and putrefactive bacteria were high, whilst counts of bifidobacteria were low. Breast-fed infants who received a supplement in the 1st week produced acid faeces, but the pH was higher than that of infants fed breast milk alone; the bacterial flora was putrefactive for the first 2 weeks but gradually became fermentative, and whilst several volatile fatty acids were detected in the faeces in the 1st week they gradually decreased during the following 5 weeks.