The development of gut microbiota in critically ill extremely low birth weight infants assessed with 16S rRNA gene based sequencing

Abstract

Objective: an increasing number of studies that are using high-throughput molecular methods are rapidly extending our knowledge of gut microbial colonization in preterm infants whose immaturity and requirement for extensive treatment may result in altered colonization process. We aimed to describe the profile of gut microbiota in 50 extremely low birth weight (<1200 g) critically ill infants at three different time points during the first two months of life by using 16S rrNa gene specific sequencing.Patients and Methods: Stool samples were collected at the age of one week, one month and two months. Bacterial community profiling was done using universal amplification of 16S rrNa gene and 454 pyrosequencing.results: The diversity of gut microbiota in preterm neonates in the first week of life was low but increased significantly over two months. The gut microbiota was dominated by facultative anaerobic bacteria (Staphylococcus spp. and Enterobacteriaceae) and lacked colonization with bacteria known to provide resistance against pathogens (Bacteroides, Bifidobacterium, and Lactobacillus) throughout the study. Colonization of Escherichia coli and uncultured Veillionella was positively correlated with maturity. Infants born to mothers with chorioamnionitis had significantly higher bacterial diversity than those without.Conclusions: High prevalence and abundance of potentially pathogenic Enterobacteriaceae and Staphylococcaceae with low prevalence and abundance of colonization resistance providing taxa bifidobacteria, Bacteroides and lactobacilli may lead to high infection risk via microbial translocation from the gut. additionally, our data suggest that maternal chorioamnionitis may have an effect on the diversity of infants' gut microbiota; however, the mechanisms involved remain to be elucidated.

Enteral High Fat-Polyunsaturated Fatty Acid Blend Alters the Pathogen Composition of the Intestinal Microbiome in Premature Infants with an Enterostomy

“…As expected for the preterm infant, Bacteroidetes were proportionately rare. 25 Using SS-ANOVA, we modeled differences in phyla abundance between the control and treatment groups over time, controlling for repeat sampling from each infant. Proteobacteria, which includes pathogenic Gram-negative bacilli, had significantly lower levels in the treatment group (Weeks 2–8, Area=−74551.1, P =0.0072).…”

Gut colonization by aerobic microorganisms is associated with route and type of nutrition in premature neonates

“…We acknowledge, that the results are applicable to a specific clinical scenario, still, one that applies to the majority of extremely preterm neonates. Third, we only included potentially pathogenic microorganisms but acknowledge that the feeding regimen will also influence the colonization of beneficial bacteria, such as bifidobacteria and lactobacilli [48]. Nevertheless, we believe that our study population well reflects those hospitalized in a third-level NICU and should add important knowledge to everyday practice.…”

The gut microbiota of hand, foot and mouth disease patients demonstrates down‐regulated butyrate‐producing bacteria and up‐regulated inflammation‐inducing bacteria

“…Bifidobacterium is a common commensal bacterium of the gut and it exerts many beneficial effects on the host . An abundance of Bifidobacterium has been shown to be reduced in many disease states, such as critically illness in extremely low birth weight infants or patients with irritable bowel syndrome . However, Yang et al.…”