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

Abstract

PLATE XXIV IT is well known that the nature of the milk fed to newborn infants greatly influences the physico-chemical and microbiological properties of their faeces. The most prominent features of the faeces of breast-fed infants in comparison with those of bottle-fed infants are a preponderance of bifidobacteria, a low pH and a virtual absence of putrefactive organisms, and it has been customary to regard this triad as sequentially related. The results of studies in vivo indicate that although pH does influence the nature of the bacterial flora, of much greater importance in this respect is the presence of an acetic acid and acetate buffer (Willis et al., 1973; Bullen, Tearle and Willis, 1976). The aim of the present study was to determine the principal source of acetic acid in infant faeces and the effect of both acetic acid and of an acetic acid and acetate buffer on the growth of certain common faecal bacteria and enteric pathogens. biotype El Tor, one laboratory strain. The laboratory strains were isolated from the faeces of infants except for the strains of C. perfringens, Salm. typhimurium, Shig. sonnei and V. cholerae El Tor, which were isolated from older patients. Acetate buflers. A series of nine acetate buffers in the range of pH 3.8-6.2 were prepared as described by Cruickshank et al. (1975). VLG medium (Beerens, et al., 1963). This fluid medium, which contains 1 % glucose, was used in 20-ml aliquots in Universal containers for the production of acetic acid by bacterial cultures. Modified reinforced clostridial medium (RCM). This was the Oxoid CM 149 formulation (Oxoid Manual, 1973) from which soluble starch, sodium acetate, and agar were omitted. It formed the nutrient basis of acetate-bufFered RCM and unbuffered RCM. Acetate-buflered RCM. Modified Reinforced Clostridial Media buffered at nine different pH values over the range of 3.8-6.2 were prepared by adding the basic ingredients to aliquots

The development of bacterial flora of premature neonates

“…By the end of the first days the predominant faecal flora was anaerobic. The contribution of the Bifidobacterium spp., Bacteroides spp., Clostridium spp., enterococci and Gramnegative aerobic organisms to the development of faecal flora in this report is essentially similar to the findings of various other studies reported by Mata, Mejicanos & Jimenez (1972), Bullen, Tearle & Willis (1976), Hentges (1980) and , on sequential development of faecal flora of healthy full-term neonates.…”

“…These studies have shown that the bacterial colonization of the various ecological niches of the body, including those of the gastrointestinal tract (GIT) and the umbilicus, occurs soon after birth. The predominant flora in the first 48 h are facultative organisms but thereafter the neonates usually become colonized by the strict anaerobes to the same, or greater, extent as the facultative species (Mata, Mejicanos & Jimenez, 1972;Bullen, Tearle & Willis, 1976;Long & Swenson, 1977;. The normal resident bacterial flora during the first 10 days of life varies according to the baby's feeds but it usually becomes stable by the end of the first month (Albert et al 1978;Beerens, Romond & Neut, 1980;Shahani & Ayebo, 1980;.…”

The development of the bacterial flora in normal neonates

“…The contributions of bifidobacteria, bacteroides, enterococci and enterobacteria were similar to those found in various studies by Mata et al (1972), Ellis-Pegler, Crabtree and Lambert (1 979, Bullen, Tearle and Willis (1 976), Long and Swenson (1977) and Albert et al (1978). Bifidobacteria are the predominant faecal bacteria in breast-fed infants (Mata and Urrutia, 197 1 ;Bullen et al, 1976) and during the first week of life in infants fed with Premium Milk (Bullen, Tearle and Stewart, 1977). In our studies, bifidobacteria represented c. 25% of all strains identified.…”

Human gut microbiota: does diet matter?

“…The gut microbiota of preterm infants is less diverse than those of full-term babies (70,73,(82)(83)(84) . There are numerous studies in which the predominance of bifidobacteria in exclusively breast-fed infants has been found (65,66,74,(85)(86)(87)(88) . At age 3-6 weeks, exclusively breast-fed infants harbour higher numbers of bifidobacteria, whereas formula-fed babies have more diverse microbiota, lower numbers of bifidobacteria and higher numbers of Bacteroides, Lachnospiraceae, Lactobacillus group, Clostridium difficile and Coriobacteriaceae (65,71,74,87,89,90) .…”