What is already known
Necrotizing enterocolitis (NEC) is a gastrointestinal condition affecting mostly premature infants. NEC is characterized by inflammation and death of intestinal tissue, which can lead to severe complications. However, unpredictable microbiota patterns make it difficult to predict who is going to develop NEC.
What this research adds
Researchers analyzed stool samples from 96 preterm infants across different neonatal intensive care units (NICUs). Preemies’ microbiotas typically shifted from high levels of Staphylococcus to the dominance of harmful microbes such as Klebsiella pneumoniae and Escherichia coli. Infants across NICUs shared strains of Staphylococcus epidermidis, indicating hospital-acquired bacteria. While microbiota features did not predict NEC, differences in microbial diversity and composition emerged in infants who developed the conditions about 40 days after birth.
Conclusions
The findings suggest that microbiota maturation plays a key role in an infant’s susceptibility to NEC. The results also indicate that the hospital environment influences the gut bacteria of preterm infants, highligting the importance of managing antibiotics and medications to support a healthy gut development.
Necrotizing enterocolitis (NEC) is a gastrointestinal condition affecting mostly premature infants that is characterized by inflammation and death of intestinal tissue, which can lead to severe complications. Now, a new study suggests that microbiota maturation plays a key role in an infant’s susceptibility to NEC.
The findings, published in Cell Host & Microbe, also indicate that the hospital environment influences the gut bacteria of preterm babies, highligting the importance of managing antibiotics and medications to support a healthy gut development.
Many preterm infants spend time in neonatal intensive care units (NICUs), where antibiotics and other medical interventions can disrupt the balance of their gut microbiota, increasing the risk for gastrointestinal conditions such as NEC. However, unpredictable microbiota patterns make it difficult to predict who is going to develop NEC.
To address this question, Robert Thänert at Washington University School of Medicine in St. Louis, Missouri, and his colleagues analyzed 1,479 stool samples from 96 preterm infants across many NICUs.
Harmful shifts
The guts of preterm infants are initially dominated by Staphylococcus species. During hospitalization in NICUs, the microbiotas of preemies shift to communities dominated by harmful bacteria such as Klebsiella pneumoniae, Enterococcus faecalis and Escherichia coli.
These changes were linked to antibiotic exposure and the presence of antibiotic resistance genes, the researchers found. However, the team also observed beneficial microbes, such as Bifidobacterium and Veillonella, emerging during hospitalization.
Preterm infants across different NICUs often shared bacterial strains, especially Staphylococcus epidermidis and Clostridioides difficile. This suggests that certain bacteria can adapt to and persist in the hospital environment.
Microbial trajectories
To further understand how hospitalization affects microbiota developement in preterm infants, the researchers used statistical methods to analyze the impact of various factors — including diet and the use of antibiotics and other medications — on microbial composition.
While maternal factors had minimal influence, antibiotic use altered the abundance of both harmful microbes and beneficial ones in the gut microbiota. While microbiota features did not predict NEC, differences in microbial diversity and composition emerged in infants who developed NEC about 40 days after birth, the researchers found.
“We comprehensively describe gut microbiome dynamics in response to medical interventions in preterm, hospitalized neonates,” the authors say. “Our findings endorse identifying and systematically correcting for variables that affect the gut microbiome development in attempts to thoroughly assess microbial community-driven outcome risks.”
