[Bifidobacteria colonization in diversely-fed newborn infants]

The aim of this work is to analyse the capacity of several formulas of stimulating the growth of bifidobacteria (Bif.), as these formulas may induced an approach to the intestinal microbiological peculiarities of breast-fed infants. This capacity has been compared with the fecal pH (fig. 2) in the various groups of artificially-fed infants and with the buffering capacity (fig. 1 a. 3) of the different milks. Six group of infants fed the following milks feed were examined: one breast-fed and five artificially-fed (table 1). Fecal specimens were examined at the 4th, 11th and 18th day of life. It is pointed out that different formulas have different capacity of stimulating the growth of Bif., both in the percentage of colonized subjects and in the developed amount of Bif. (tab. 2). It is exhibited a mutual relation between this capacity of a food and the fecal pH (fig. 3) in newborn infants fed on this food. On the contrary it is not easy to find a clear relation between the capacity of growth of Bif. and the buffering properties of a milk: two of the tested milks have nearly the same buffering capacity but allow completely different colonisation (fig. 1 a. 3). It is suggested that if this mutual relation was real, we must think of "how" this buffer capacity is realized and not of its absolute value. Although several Authors proved that there is a "in vitro" antagonism between Bif. and E. coli, it is not confirmed this statement "in vivo" (fig. 2 a. 3).(ABSTRACT TRUNCATED AT 250 WORDS)