The impact of gut microbiota in full-term pregnant women on immune regulation during pregnancy: A prospective, exploratory study

Abstract

Aim

This study aims to investigate the correlation between gut microbiota and both placental local immune function and the maternal systemic immune system in pregnant women.

Methods

Twenty-six pregnant women were included in this study, utilizing high-throughput sequencing for gut microbiota analysis. Immune cells and cytokine levels were measured in placental tissue and peripheral venous blood. Integration of gut microbiota data with immune parameters was performed using R, and network correlation analysis was conducted with Cytoscape software.

Results

In placental tissues, gut microbiota predominantly influences B lymphocytes (CD3−CD19+/CD3−), indicating a potential bidirectional regulatory role. The impact on CD56+CD16+/CD56+CD16− and CD4+/CD8+ ratios appear minor. Notably, a significant positive correlation was observed between gut microbiota and the placental cytokine interleukin (IL)-5. In peripheral blood, gut microbiota was primarily associated with negative regulation of peripheral B lymphocytes and positive regulation of peripheral Treg cells. Minimal effects are observed on peripheral macrophages and NK cell subtypes. The most substantial impact on peripheral immune balance was reflected in the CD4+/CD8+ ratio, showing a predominant negative correlation, while the influence on the CD56+CD16+/CD56+CD16− ratio is minimal. A significant negative correlation was found between gut microbiota and peripheral cytokines IL-1 and IL-18, while the interaction with the peripheral interferon-γ/IL-4 ratio appears relatively less pronounced.

Conclusions

The close correlation between gut microbiota and placental local immune function, as well as maternal systemic immune responses, is evident. This study contributes to a preliminary understanding of the immunomodulatory relationship of gut microbiota during pregnancy.