Microbiomic insights into the unique effects of vaginal microbiota on preterm birth in Chinese pregnant woman

Jun Zhang Zhimin Xu Mengjun Zhang Jiaoning Fang Yijing Zheng Caihong Jiang Mian Pan ^*

• Department of Obstetrics and Gynecology, Fujian Maternity and Child Health Hospital, Fujian, China

Preterm birth is a mainly reason of perinatal morbidity and mortality. The disorder of vaginal microbiota in pregnant women is the most important risk factor for preterm delivery. In this study, 65 cases of pregnant women were enrolled, of which 29 cases of women with term births and 36 cases of women with preterm births according to the gestational age at delivery. The results displayed that the α-diversity (Ace, Chao1, Simpson and Shannon indices) of vaginal microbiota in the term birth groups (TG) was dramatically higher than that in the preterm birth group (PG). The relative abundance of beneficial bacteria (e.g., Lactobacillus) was significantly reduced in the PG group compared with the TG group, but harmful bacteria (e.g., Gardnerella, Atopobium, Ralstonia, Sneathia, et al) was significantly increased. A prediction model for gestational age at delivery was established based on key microbial phylotypes, and this model was further verified using clinical samples. Statistical analysis revealed the prediction model derived from Methyloversatilis, Atopobium, Ralstonia, Sneathia, Brevundimonas, Gardnerella, Acinetobacter, and Peptostreptococcus have higher accuracy. These results elaborate that some potential bacteria could serve as prospective predictors for preterm birth and provide the theoretical basis for the treatment of preterm birth.