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

Abstract

A qualitative molecular monitoring approach based on PCR and denaturing gradient gel electrophoresis (DGG E) was used to study the diversity of dominant bacteria, bi dobacteria and lactobacilli in vaginally delivered full-term infants. Seven breast-fed and six formula-fed infants participated in the study. 16S rDNA targeted primers were used for the speci c PCR ampli cation of fragment s from bacteria, bi dobacteria and lactobacilli from faeca l samples that were collected before and after weaning at the age of approximat ely 1 and 7 months, respectively. The PCR fragment s were subsequently resolved in a sequence-dependen t manner by D GGE. In addition, cloning and sequence analysis of the PCR fragment s was used to identify the species from which they originated. Based on the number of fragment s in the D GGE pro les it was estimated that breast-fed and formula-fed infants harboured bacterial communities of equa l complexity. There was no conspicuou s difference in the distribution of Bi dobacterium or Lactobacillus species between breast-fed and formula-fed infants. The most frequently found representat ives of these gener a were B. infantis and species belonging to the L. acidophilus -group in both groups of infants. The predominan t Bi dobacterium and Lactobacillus populations in most infants consisted of only one or two species.

Determinants of the human infant intestinal microbiota after the introduction of first complementary foods in infant samples from five European centres

“…We also observed that during weaning, breastfeeding induced a slower increase of C. leptum and a faster reduction of C. difficile and C. perfringens species compared with formula or mixed feeding. Satokari et al (2002) reported similar changes in the microbiota during weaning between breastfed and formula-fed infants. In a group of children at 6 months, where half had started to have the breast milk supplemented with solid food, George et al (1996) observed that the number of enterococci and Bacteroides increased, whereas enterobacteria and bifidobacteria remained constant.…”

“…This is reflected in the microbiota composition and profiles of short chain fatty acids (Midtvedt & Midtvedt, 1992). There are, however, very little data on changes in the composition of the intestinal microbiota during early weaning (Satokari et al, 2002;Wang et al, 2004;Ahrné et al, 2005) and how the influence of pre-weaning feeding methods and perinatal events impact on the microbiota after the introduction of complementary foods.…”

The role of early life nutrition in the establishment of gastrointestinal microbial composition and function

“…While there were marked differences between the EBF and EBF C S groups, the separation between clusters of non-EBF and non-EBF C S groups was more distinct. The lack of any significant microbiota changes accompanying the introduction of complementary foods reported in BF infants by some groups 22,43 further supports the impact of HM withdrawal. Others have found that infants still receiving HM at 9 mos harbored lower levels of butyrateproducing bacteria, C. leptum, C. coccoides, and Roseburia, as well as Bacteroidetes 45 which have been previously noted to increase when infants begin to consume solid foods.…”

“…58 Infants harboring similar relative abundances of Bifidobacterium still exhibit some variance in diversity, 34,39,42 and stability 51 of populations at the species level. For example, B. longum and B. breve are the dominant species in BF infants, 27,[41][42][43] whereas FF infants also harbor adultassociated bifidobacterial species, such as B. adolescentis. 24,39,42 While many studies have focused on bifidobacterial colonization, breastfeeding supports other differences in microbiota composition.…”

“…Increased proportions of Lactobacillus, 25,26,48,54 as well as greater abundances of L. gasseri 28,47 in BF compared to FF infants have been reported, whereas other studies found opposite results 16,52,53 or reported intergroup variability and instability over time. 27,43 A greater prevalence 15 and higher proportion 24 and total counts 16,46 of C. difficile in FF compared to BF infants, as well as, significantly more Peptostreptococcaceae, 31 Akkermansia, 15 Veillonella, and Enterococcus 28 have been described. Escherichia abundance was also higher in FF than BF infants 28 and decreased at a slower rate over time.…”