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A Method for Targeted 16S Sequencing of Human Milk Samples
Published on: March 23, 2018
The development of gut microbiota in critically ill extremely low birth weight infants assessed with 16S rRNA gene
Tiina Drell1, Irja Lutsar2, Jelena Stšepetova2
1Institute of Microbiology; University of Tartu; Tartu, Estonia; Centre for Biology of Integrated Systems; Tallinn University of Technology; Tallinn, Estonia; Competence Centre on Reproductive Medicine and Biology; Tartu, Estonia.
Insights
The gut microbiota of extremely low birth weight infants shows low diversity initially, increasing over two months but lacking beneficial bacteria. Maternal chorioamnionitis may impact infant gut microbial diversity.
Area of Science:
- Microbiology
- Neonatal Research
- Genomics
Background:
- Preterm infants often have altered gut microbial colonization due to immaturity and medical interventions.
- High-throughput molecular methods are crucial for understanding these complex microbial communities.
Purpose of the Study:
- To characterize the gut microbiota profile in extremely low birth weight (ELBW) infants.
- To analyze microbial changes over the first two months of life using 16S rRNA gene sequencing.
Main Methods:
- Collected stool samples from 50 ELBW infants at one week, one month, and two months of age.
- Utilized 16S rRNA gene amplification and 454 pyrosequencing for bacterial community profiling.
Main Results:
- Gut microbial diversity was low in the first week, increasing significantly by two months.
- Facultative anaerobic bacteria (Staphylococcus, Enterobacteriaceae) dominated; beneficial bacteria (Bacteroides, Bifidobacterium, Lactobacillus) were scarce.
- Escherichia coli and Veillonella colonization correlated with infant maturity; maternal chorioamnionitis increased infant gut microbial diversity.
Conclusions:
- The gut microbiota composition in ELBW infants poses a high infection risk due to pathogenic bacteria dominance and lack of colonization resistance.
- Maternal chorioamnionitis appears to influence infant gut microbial diversity, warranting further investigation into the underlying mechanisms.
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.
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