Delivery mode shapes the acquisition and structure of the initial microbiota across multiple body habitats in newborns

Abstract

Upon delivery, the neonate is exposed for the first time to a wide array of microbes from a variety of sources, including maternal bacteria. Although prior studies have suggested that delivery mode shapes the microbiota's establishment and, subsequently, its role in child health, most researchers have focused on specific bacterial taxa or on a single body habitat, the gut. Thus, the initiation stage of human microbiome development remains obscure. The goal of the present study was to obtain a community-wide perspective on the influence of delivery mode and body habitat on the neonate's first microbiota. We used multiplexed 16S rRNA gene pyrosequencing to characterize bacterial communities from mothers and their newborn babies, four born vaginally and six born via Cesarean section. Mothers’ skin, oral mucosa, and vagina were sampled 1 h before delivery, and neonates’ skin, oral mucosa, and nasopharyngeal aspirate were sampled <5 min, and meconium <24 h, after delivery. We found that in direct contrast to the highly differentiated communities of their mothers, neonates harbored bacterial communities that were undifferentiated across multiple body habitats, regardless of delivery mode. Our results also show that vaginally delivered infants acquired bacterial communities resembling their own mother's vaginal microbiota, dominated by Lactobacillus , Prevotella, or Sneathia spp., and C-section infants harbored bacterial communities similar to those found on the skin surface, dominated by Staphylococcus , Corynebacterium , and Propionibacterium spp. These findings establish an important baseline for studies tracking the human microbiome's successional development in different body habitats following different delivery modes, and their associated effects on infant health.

Gut microbiota: a source of novel tools to reduce the risk of human disease?

“…However, microbial colonization of the human infant may begin earlier. The dogma of sterile intrauterine environment has recently been challenged by reports on detection of diverse microbes in placenta, umbilical cord, amniotic fluid, and meconium (3)(4)(5)(6)(7)(8)(9)(10). Taking these preliminary observations together, the contact with the complex bacterial communities is clearly already initiated in utero and the impact of maternal microbiota may be more important than we had previously believed.…”

“…Recently, more attention has been given to differences in early microbial contact related to the mode of birth. An accumulating body of evidence indicates that vaginally and surgically delivered neonates exhibit distinct gut colonization patterns (6,7,33,44,45). The differences in gut microbiota composition may still be observed at the age of 7 y (46).…”

Human gut microbiota: does diet matter?

“…regardless of the infant's geographical origin and methods used for the detection (65,(75)(76)(77)(78)(79)(80) . Immediately after birth, the rectal microbiota of vaginally delivered babies resembles their own mother's vaginal microbiota, whereas the rectal microbiota of babies delivered by Caesarean section resembles that of the skin (81) . The gut microbiota of preterm infants is less diverse than those of full-term babies (70,73,(82)(83)(84) .…”

Modulatory Effects of Gut Microbiota on the Central Nervous System: How Gut Could Play a Role in Neuropsychiatric Health and Diseases

“…[13][14][15][16] Germ-free mice show developmental abnormality in the GI tract that can be reversed by reconstructing the gut microbiota, suggesting a role for gut microbiota in postnatal development of the enteric nervous system (ENS). 17,18 This period is also critical for the development of the CNS leading to the suggestion, based on experimental models, that gut microbiota may be an important factor participating in the development of cognitive, emotional, and behavioral processes shortly after birth.…”