Bifidobacteria in the intestinal tract of infants: an in-vivo study

Abstract

Weekly fecal specimens from 18 babies were examined during the first 8 wk of life. Eight infants were breast fed, 10 were bottle-fed. All suckling infants received supplementary feeds for the first 8 days. A buffer consisting of acetic acid and acetate was demonstrated in the feces of all the breast-fed infants at some time during the period of examination. This buffer was rarely detected during the 1st wk of life when supplementary feeds were given, and buffer already present gradually disappeared with the introduction of mixed feeding. At no time was an acetate buffer demonstrated in the feces of bottle-fed infants. Babies receiving breast milk produced feces with low pH, high counts of saccharolytic organisms including bifidobacteria and Streptococcus faecium, and low counts of Escherichia coli, Bacteroides and clostridia. Bottle-fed infants produced feces with a high pH and high counts of E. coli and putrefactive bacteria but low counts of bifidobacteria.