Ronde Emma, Alkema Maaike, Dierikx Thomas, Schoenmakers Sam, Belzer Clara, de Meij Tim
Division of Obstetrics and Prenatal Diagnosis, Erasmus University Medical Centre, Dr. Molewaterplein 40, Rotterdam, 3015 GD, The Netherlands.
Laboratory of Microbiology, Wageningen University, Dreijenplein 10, Wageningen, 6703 HB, The Netherlands.
BMC Pregnancy Childbirth. 2025 Mar 8;25(1):254. doi: 10.1186/s12884-025-07358-w.
Early life microbial colonization of the neonatal gastrointestinal tract is crucial for imprinting of the immune system. Vertical transmission of maternal microbes is considered the key source of initial neonatal microbial colonization. We aimed to evaluate the role of the maternal vaginal and rectal microbiota in early neonatal gastrointestinal colonization in vaginally- and caesarean section-born neonates.
Maternal vaginal and rectal swabs were collected shortly before delivery. Neonatal fecal samples were collected at day 0, 7 and 28 postnatally in both vaginally-born (n = 23) and caesarean-section born (n = 40) neonates (total n = 63). All samples were analyzed by 16 S rRNA sequencing. The relative abundances of amplicon sequence variants (ASVs) shared between maternal swabs and fecal neonatal samples were compared in vaginally-versus caesarean section-born neonates.
The median relative abundance of ASVs shared in the maternal rectal and vaginal swabs with all neonatal samples was low (below 10% for rectal or vaginal swabs with any of the three time-points). When focusing on vaginally- versus caesarean section-born neonates, there were no differences in the relative abundance of shared ASVs with the maternal vaginal swabs, and only on day 7 in the rectal swabs (p = 0.002). However, in both delivery routes, the relative abundance of ASV shared with the maternal rectal swab was higher (median 19% in vaginally-born neonates and 2% in caesarean section-born neonates) compared to the relative abundance of the ASVs shared with the maternal vaginal swab (0% for both vaginally- and caesarean section-born neonates) on day 28.
We observed that only a limited amount of ASVs were transferred from maternal rectal and vaginal compartments to the neonatal gastrointestinal tract. ASVs from the maternal gastrointestinal tract contributed to neonatal gut colonization to a greater extent than ASVs from the maternal genital tract at one month of age. Our findings contribute to an increased understanding of factors influencing neonatal gastrointestinal colonization in both caesarean section and vaginal birth, of importance as characteristics of early colonization have been associated with health outcomes later in life.
The original trial is registered with the Dutch Clinical Trial Registry (Trial registration number: NTR6000, https://www.trialregisternl/trial/5845 ) and the study protocol was published online.
新生儿胃肠道的早期微生物定植对于免疫系统的印记形成至关重要。母体微生物的垂直传播被认为是新生儿初始微生物定植的关键来源。我们旨在评估母体阴道和直肠微生物群在阴道分娩和剖宫产出生的新生儿早期胃肠道定植中的作用。
在分娩前不久采集母体阴道和直肠拭子。在出生后第0天、第7天和第28天，采集阴道分娩（n = 23）和剖宫产出生（n = 40）的新生儿（共n = 63）的粪便样本。所有样本均通过16S rRNA测序进行分析。比较阴道分娩与剖宫产出生的新生儿中母体拭子和新生儿粪便样本之间共享的扩增子序列变体（ASV）的相对丰度。
母体直肠和阴道拭子与所有新生儿样本共享的ASV的中位相对丰度较低（在三个时间点中的任何一个时间点，直肠或阴道拭子的相对丰度均低于10%）。当关注阴道分娩与剖宫产出生的新生儿时，与母体阴道拭子共享的ASV的相对丰度没有差异，仅在第7天直肠拭子中有差异（p = 0.002）。然而，在两种分娩方式中，与母体直肠拭子共享的ASV的相对丰度在出生后第28天均高于与母体阴道拭子共享的ASV的相对丰度（阴道分娩的新生儿中中位数为19%，剖宫产出生的新生儿中为2%）（阴道分娩和剖宫产出生的新生儿与母体阴道拭子共享的ASV的相对丰度均为0%）。
我们观察到只有有限数量的ASV从母体直肠和阴道区域转移到新生儿胃肠道。在出生一个月时，来自母体胃肠道的ASV比来自母体生殖道的ASV对新生儿肠道定植的贡献更大。我们的研究结果有助于增进对影响剖宫产和阴道分娩新生儿胃肠道定植因素的理解，这很重要，因为早期定植的特征与生命后期的健康结果相关。
原始试验已在荷兰临床试验注册中心注册（试验注册号：NTR6000，https://www.trialregisternl/trial/5845 ），研究方案已在线发表。
