Composition of the microbial communities at different body sites in women with preterm birth and their newborns

Objective

In this study, we aimed to examine the changes in the composition of vaginal and gut microbiota during the third trimester of pregnancy among women who delivered preterm. To further understand the relationship of these changes to preterm birth, we analyzed the microecology of vaginal and gut microbiota in mothers, as well as oral and gut microbiota in their newborns, and then compared the microecological characteristics of the microbiome at different body sites between the mothers and their newborns, as well as between the mothers and between the newborns from different groups.

Methods

In total, 26 women who delivered at Zhujiang Hospital, Southern Medical University (China) from July 2020 to January 2021 were categorized into the preterm and term groups. A blank swab and laboratory air and water samples were collected as part of the control group. We collected maternal vaginal and rectal samples, as well as neonatal oral and rectal samples. Total DNA from different parts of the swabs was extracted and sequenced using the 16s rRNA technique. Then, the data was analyzed using bioinformatics and statistical analysis.

Results

The abundance and alpha diversity of vaginal microbiota in the preterm group was found to be higher, but the difference was not statistically significant. There were significant differences in beta diversity of vaginal microbiota between the two groups (p ​< ​0.05). The levels of Rothia and Gemella in the gut microbiota of women who had delivered preterm were significantly lower (p ​< ​0.05). The alpha diversity of gut microbiota and neonatal oral and gut microbiota in women who had delivered preterm was lower. No significant differences were observed in alpha and beta diversity between the two groups in maternal gut microbiota and neonatal oral and gut microbiota. In the newborns in both groups, some species of oral microbiota were consistent with their mother's vaginal microbiota, and some species of gut microbiota in the newborns in both groups were consistent with their mother's gut microbiota.

Conclusions

Vaginal and gut microbiota in women who had given birth preterm were noticeably different from the vaginal and gut microbiota of women who had delivered at term, and it was probably related to preterm birth. Oral and gut microbiotas of preterm newborns were also noted to be different from that of the term newborns. It suggests that the changes in the microbiome of the newborns could be related to preterm birth. Some part of the newborns’ microbiota probably originates in the uterus.