Factors Influencing the Composition of the Intestinal Microbiota in Early Infancy

Abstract

The most important determinants of the gut microbiotic composition in infants were the mode of delivery, type of infant feeding, gestational age, infant hospitalization, and antibiotic use by the infant. Term infants who were born vaginally at home and were breastfed exclusively seemed to have the most "beneficial" gut microbiota (highest numbers of bifidobacteria and lowest numbers of C difficile and E coli).

Caesarean section is associated with an increased risk of childhood-onset type 1 diabetes mellitus: a meta-analysis of observational studies

“…The gut microbiota are thought to play an important role in stimulating the development of the immune system [48]. Recent studies have shown that the gut microbiotic composition differ in children born by Caesarean section compared with vaginally born children [8][9][10][11], perhaps because such children are first exposed postpartum to bacteria originating from the hospital environment rather than to maternal bacteria [11]. This difference in gut microbiotic composition could increase the risk of type 1 diabetes.…”

“…Animal models suggest a higher risk of diabetes after Caesarean section [6,7]. Also, children delivered by Caesarean section have been shown to have altered gut microbiotic composition and immune function [8][9][10][11], which could increase their risk of type 1 diabetes. Numerous studies have investigated Caesarean section and type 1 diabetes, but findings have been inconsistent, possibly as a result of inadequate size and limited power in some studies.…”

Human gut microbiota: does diet matter?

“…mode of delivery, prematurity, type of feeding (breast feeding v. formula feeding), antibiotic treatment of the child or the mother, lifestyle and geographics (65,(69)(70)(71)(72)(73)(74) . The earliest colonisers are usually facultative anaerobic bacteria such as Enterobacteriaceae, streptococci and staphylococci, whereas later colonisers tend to be strict anaerobes e.g.…”

“…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) . By the end of the first year of life, when the child has already started to eat the same foods as the adults, the gut microbiota starts to converge towards a profile characteristic of the adult microbiota (76,90) .…”

Enterotoxigenic Bacteroides fragilis: A potential instigator of colitis

“…5,6 Colonization rates in children have been less well studied. 7 Although humans are typically asymptomatically colonized, B. fragilis is identified as the leading anaerobe in bloodstream infections and intraabdominal abscesses. [8][9][10] A molecular subset of B. fragilis, termed enterotoxigenic B. fragilis (ETBF), secrete a 20-kDa proinflammatory zinc-dependent metalloprotease toxin, designated the B. fragilis toxin (BFT).…”