The Composition of the Faecal Microflora in Breastfed and Bottle Fed Infants from Birth to Eight Weeks

Abstract

Recent technical advances have improved the possibilities to classify anaerobic bacteria. The aim of the present study was to examine the validity of the time-honoured opinion that the faecal flora is dominated by bifidobacteria in breastfed infants but not in bottle fed ones. The composition of the faecal flora of 15 breastfed and of 7 bottle fed infants was followed from birth to 8 weeks. Strictly anaerobic conditions were carefully applied. At 5 days and 3 weeks the incidence of Staph. epidermidis was significantly greater in the breastfed group compared to the bottle fed one. We were unable to confirm earlier reports of difference in the anaerobic flora between breastfed and bottle fed infants. In both feeding groups Bacteroides dominated among the anaerobic bacteria and bifidobacteria occurred in less than half of the faecal specimens. The results of the study add to other recent observations that it has been increasingly difficult to demonstrate bifidobacteria in babies delivered in large, urban hospitals. We found different frequencies of bifidobacteria in infants from different wards, suggesting the importance of environmental factors in gut colonization after delivery.

Diversity of Bifidobacterium and Lactobacillus spp. in Breast-Fed and Formula-Fed Infants as Assessed by 16S rDNA Sequence Differences

“…The dot blot analysis con rmed our nding that two breast-fed infants, coded 1 and 52, and one formula-fed infant, coded 49 were not colonised by bi dobacteria at the age of 1 and:or 7 months (31). Our results are in line with several studies that show equal, either high (7,8) or low (9,13,27), frequency of bi dobacterial colonisation in both groups. Previous observations that the bi dobacterial populations of infants generally consist of one to three species (30,32,33) are con rmed by our ndings.…”

“…H owever, several other culture based studies have shown that both groups of infants have equal frequency and level of bi dobacterial colonisation by the age of approximately 1 month or earlier (7)(8)(9). Con icting results have also been obtained regarding other groups of bacteria such as Bacteroides, clostridia, enterococci, lactobacilli and enterobacteria in breast-fed and formula-fed infants.…”

“…M oreover, in some studies formula-fed infants were found to have more complex faecal short-chain fatty acid (SCF A) pro les than breast-fed infants, which indicates a more complex microbiota in the aforementioned group (11,12). In contrast, earlier studies based on cultivation showed no difference in the composition of anaerobic and facultative anaerobic bacteria between breast-fed and formula-fed infants (9,13).…”

“…F irstly, the composition of infant formulae has been improved over the years (25,26), which is likely to have led to a more breast-fed-like colonisation pattern in formula-fed infants. Secondly, delivery with few exposures to microbes due to the use of vaginal antiseptics at the time of birth or caesarean section can lead to an altered intestinal colonisation in infancy (9,27,28). F inally, there are signi cant geographical differences in the composition of intestinal microbiota of infants (13,29).…”

Asthma and atopy – the price of affluence?

“…Major differences in the composition of the gut flora were found between infants who developed and those who did not develop allergy, and these differences were discernible before any clinical manifestation of atopy could be observed (103). The differences in the intestinal flora in early life were proposed to be associated with Western lifestyle including such factors as the high hygiene control during delivery and high consumption of industrially processed and sterilized food in early life (104,105). Lactobacilli have raised considerable interest in recent years as immunomodulatory agents.…”