Methods
A prospective study aimed to investigate differences in gut microbiomes between neonates born via vaginal and cesarean delivery. We included term neonates delivered at the Srinakharinwirot University Hospital, Thailand, between February 2021 and April 2023. The study was approved by the Institutional Review Board (SWUEC-M/029/2564E) and registered with the Thai Clinical Trials Registry (TCTR20221024003). The sample size was calculated based on a gut Bifidobacterium prevalence of 36.6% in infants delivered by vaginal delivery compared to one of 48.6% in infants delivered by cesarean delivery (7), which resulted in samples of at least 131 for each group.
All healthy term neonates delivered at the institution were included. We excluded neonates born to mothers with prior infections, those whose mothers received antibiotics for cesarean delivery (except for pre-operative prophylaxis), those unable to provide a fecal specimen within 48 hours post-delivery, and those with neonatal complications or previous antibiotic use. Written consent was obtained from the mothers, and each patient’s demographic data, route of delivery, neonatal outcomes, and timing of fecal collection were collected.
The study processes after data collection were fecal collection, genomic DNA extraction, purification, 16S ribosomal ribonucleic acid (rRNA) amplification, 16S rRNA library preparation, and sequencing (Figure 1).