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. 2025 Aug;32(8):2729-2741.
doi: 10.1007/s43032-025-01869-9. Epub 2025 Apr 22.

Correlation between Lactobacillus of Vaginal Microbiota and the Pregnancy Outcomes for Patients Experiencing Recurrent Miscarriage

Jifan Tan  1   2   3 , Ruyun Chen  1   2 , Dehai Gan  1   2 , Miaoxian Ou  1   2 , Yue Wu  1   2 , Huiying Jie  1   2 , Yanwen Xu  4   5 , Jia Huang  6   7
Affiliations

Correlation between Lactobacillus of Vaginal Microbiota and the Pregnancy Outcomes for Patients Experiencing Recurrent Miscarriage

Jifan Tan et al. Reprod Sci. 2025 Aug.

Abstract

The etiology of recurrent miscarriage (RM) is complex, with the vaginal microbiota (VM) being an important factor associated with RM. We aimed to establish the VM composition in both patients with RM and healthy women and further investigate relationship between the subsequent pregnancy outcomes of patients with RM and VM, to explain the potential mechanism of VM in RM to some extent. A cohort study compared the VM between 34 patients with RM and 15 healthy women using a sequencing technique based on Type IIB restriction enzymes for the microbiome (2bRAD-M). Further comparison was made between 11 patients with clinical miscarriages (CM) and 13 patients with ongoing pregnancies (OP) in the RM group who conceived naturally. To determine the VM composition, the 2bRAD-M library was prepared, and sequence and bioinformatics analyses were conducted. The composition of the VM exhibited notable differences between the non-RM and RM groups, with significant findings for alpha diversity (p < 0.05) and beta diversity (p = 0.01). Further analysis between the RM-OP and RM-CM groups revealed a significant difference in Lactobacillus (97.81% ± 2.71% vs. 53.37% ± 46.42%, p = 0.03). Other uncommon species, such as Cutibacterium acnes (C. acnes) (p = 0.04) were found significantly increase in the RM-CM group. Functional annotation analysis revealed 47 related signaling pathways between the two groups. The results of this study indicate that Lactobacillus is associated with subsequent miscarriages and that C. acnes is closely related to pregnancy outcomes of patients with RM.

Keywords: Bifidobacterium; Lactobacillus; Recurrent miscarriage; Vaginal microbiota.

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Conflict of interest statement

Declarations. Ethics Approval: This study was approved by the Ethics Committee of Reproductive Medicine, the First Affiliated Hospital of Sun Yat-sen University (No. [2023]620). Consent to Participate: Informed consent was obtained from all participants included in the study. Consent to Publish: Patients signed informed consent regarding publishing their data. Competing interests: There are no conflicts of interest to declare.

References

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