Enterococcus faecalis Is a Better Competitor Than Other Lactic Acid Bacteria in the Initial Colonization of Colon of Healthy Newborn Babies at First Week of Their Life

Abstract

Initial colonization of human gut by bacteria is an important step in controlling its microbiota and health status. This study followed the initial colonization by lactic acid bacteria (LAB) in colon of new born babies through following its occurrence in their stool at first week of their life. The LAB occurrence in the neonates’ stool was followed on MRS agar medium. The isolated LAB from male and female newborn babies of normal birth and cesarean section surgical delivery were molecular biologically identified by phylogenetic analysis of 16S rRNA gene sequence. From the 24 investigated newborn babies, three LAB taxa, Lactobacillaceae , Enterococcus , and Streptococcus , were detected in their stool at first week of their life. Lactobacillaceae represented 20.8% of total colonized LAB in newborn babies in the culture-dependent approach used in this study and included three species namely Limosilactobacillus reuteri (previously known as Lactobacillus reuteri ), Lacticaseibacillus rhamnosus (previously known as Lactobacillus rhamnosus ) and Ligilactobacillus agilis (previously known as Lactobacillus agilis ). Enterococcus faecalis and E. faecium were detected where E. faecalis was the highest dominant, representing 62.5% of total LAB colonizing newborn babies. This result suggests that this bacterium has high potency for colonization and might be important for controlling the initial settlement of microbiota in healthy newborn babies. Only one species of Streptococcus namely Streptococcus agalactiae was detected in 8.33% total of the investigated newborn babies indicating high competency by other LAB for colonization and that this bacteria, in spite of its pathogenicity, is commensal in its low existence in healthy babies. The explored potency of natural initial colonization of the LAB species E. faecalis , E. faecium , L. reuteri , L. rhamnosus , and L. agilis of which many health beneficial strains were previously reported, would be important for future applications. Despite the controversy in evaluating its health benefits, E. faecalis as a potent competitor to other LAB refers to its importance in initial colonization of healthy babies colon at first week of their life. Further future studies, with more number of samples and characterization, would be of importance for evaluating the potential use of beneficial Enterococcus strains which could improve intestinal ecosystem.

Prenatal versus Postnatal Initial Colonization of Healthy Neonates’ Colon Ecosystem by the Enterobacterium Escherichia coli

“…No E. coli or other enteric bacteria were detected in first-pass meconium on eosin-methylene blue (EMB) agar, LB agar, or MacConkey agar. The first-pass meconium also showed no viable lactic acid bacteria (LAB) on de Man Rososa Sharpe (MRS) agar medium in this study or in a previous study ( 29 ) where LAB were detected in second-day stool and later. Despite several reports presenting a microbiome in placenta, amniotic fluid, and meconium, the viability and function of these microbiomes is not fully clear yet.…”

The Many Faces of Enterococcus spp.—Commensal, Probiotic and Opportunistic Pathogen

“…Pregnant women, newborns, and the elderly are typically at greater risk of infection due to undeveloped or weakened immune systems. Research has demonstrated that supplementation with probiotics in the elderly leads to the growth of potentially beneficial intestinal bacteria but also leads to the increased activation of a non-specific immune response [ 71 ]. In some Western European countries, a fermented milk drink called “Gaio” (yogurt) is available, containing bacteria called “Causido,” which includes the E. faecium K-77D strain and two strains of Streptococcus termophilus .…”

Pre- versus postnatal initial colonization of healthy neonates’ colon ecosystem by the enterobacterium Escherichia coli

“…Thus, E. coli might in addition to other facultative anaerobes act as initial servant bacterium which consumes molecular oxygen gas for installing anaerobiosis for colon colonization by microaerobic and anaerobic bacteria such as Lactobacilli. The Lactobacilli are of the initial colonizing bacteria of colon in healthy newborn babies [8]. Lactobacillus sp is usually found in babies colon where it plays important healthy roles [53,54].…”

“…This ability of E. coli to utilize lactose might help for its early colonization of the neonates' colon. Thus, along with early colonization of the neonates' colon by lactic acid bacteria (LAB) [8], E. coli also has suitable nutritional conditions explaining their good ability for initial colonization of the neonates' colon where milk retaining lactose is the only diet provided to the neonates through either breast or formula feeding. This also support our conclusion that initial colonization of E. coli is postnatal where milk feeding of the newborn babies confers a viable nutritional requirement of this bacterium and many other health bene cial lactose fermenting taxa.…”

“…The human colon as a microbial ecosystem retains a microbial community playing important roles for body health [1][2][3][4][5][6][7][8]. The initial colonization of the colon by bacteria is important in formulating the microbial community where this initial bacterial colonization is a complicated process in correlation with some factors that might affect the establishment of the microbiome within the colon of the neonate [9][10][11].…”