Findings of a prospective birth cohort study presented at the European Congress of Clinical Microbiology & Infectious Diseases suggested that infants born through caesarean section have an altered gut microbiota that may leave them more susceptible to respiratory infections in the first year of life.
The link between mode of delivery and infant gut microbiome development has been documented in previous research as well. In 2018, WHO released guidance on reducing the number of cesarean sections performed to improve both maternal and infant health because many of these procedures are not medically justified.
Debby Bogaert, MD, PhD, a Scottish senior clinical fellow and honorary consultant in pediatric infectious diseases at the University of Edinburgh, told Infectious Diseases in Children that cesarean sections should be limited to only those who medically need them.
“There is high variation in cesarean section rates between countries, which cannot only be explained by differences in medical indications,” she said.
Bogaert said limiting caesarean sections could prevent the colonization of potentially harmful bacteria in infants and ensure that they are colonized with the bacteria they need for healthy gut functioning.
The researchers collected fecal samples from 46 infants born by cesarean section and 74 infants who were vaginally delivered. The samples were collected at various points during the infants’ first year of life. Two weeks after delivery, the researchers also collected fecal samples from mothers who were not administered antibiotics until after cord clamping.
They found a statistically significant difference in microbiota composition over the first year between infants born through cesarean section and vaginal delivery. The difference was the most pronounced during the first week of life, the researchers said. Infants born through vaginal delivery showed evidence of fecal seeding from mother to child, but this was not observed in infants born through cesarean section. Because the overall gut microbiota composition did not differ between mothers who gave birth through vaginal delivery or cesarean section, the seeding appeared independent of IV antibiotic administration in the cesarean section group.
Gut microbiota was less stable among infants born through cesarean section, and these infants had a delay in the acquisition of Bifidobacterium species, which are believed to exert positive health benefits on their host. Infants born through cesarean section also had a higher prevalence of possibly pathogenic bacteria, including Klebsiella and Enterococcus species. The abundance of these bacteria was independently associated with length of hospital stay, feeding type and antibiotic use, according to the researchers.
Bogaert and colleagues observed a link between microbiota composition at age 1 week and the number of respiratory infections in the first year. The type of Klebsiella and Enterococcus that were primarily responsible for this relationship were more abundant in infants born through cesarean section.
Bogaert said more research is needed to better understand how to reduce the harmful effects of cesarean section and restore a healthy gut microbiome. – by Katherine Bortz
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Reyman AM, et al. Abstract 6550. Presented at: ECCMID; April 13-16, 2019; Amsterdam, Netherlands.
Disclosures: Bogaert reports receiving unrestricted fees paid to her institution for advisory work from Friesland Campina, as well as research support from Nutricia. None of the grants were used for this research.