MICROBIAL transmission and oral microbiota alterations might have links to immune changes in pregnancy according to new research.
Oral Microbiota and Maternal Immune Profiles
Researchers evaluated associations between the oral microbiota, salivary metabolites, potential oral-gut transmitted microbes, and immune alterations in women at term pregnancy. The study included 25 pregnant women and 25 non-pregnant women. Investigators profiled oral and gut microbiomes, the salivary metabolome, peripheral immune cells, and cytokines.
Several bacterial species that become enriched during pregnancy demonstrated significant associations with immune cell populations. Streptococcus anginosus and Prevotella denticola were positively correlated with the natural killer cell ratio. In addition, Prevotella histicola and Prevotella micans showed positive correlations with CD56brightCD16− natural killer cells.
These findings demonstrate associations between pregnancy enriched oral bacterial species and natural killer cell populations.
Salivary Metabolites Show Limited Mediating Role
The investigators also explored whether salivary fatty acids could explain the relationship between oral microbiota changes and peripheral immune alterations.
Mediation analysis indicated that fatty acids in saliva may not mediate the impact of the oral microbiota on systemic immune changes during pregnancy.
Evidence for Oral-Gut Microbial Transmission
The study further identified several potential oral-gut transmitted microbes with higher maternal transfer ratios. These microbes were positively associated with CD56brightCD16− natural killer cells and the overall natural killer cell ratio. Conversely, they were negatively associated with T helper Type 1 cells and the T helper Type 1 to T helper Type 2 ratio.
Conclusion
Overall, this study highlights the potential associations between immune markers and oral-gut transmitted microbes during pregnancy. Researchers called for larger and more diverse populations to be used in future studies to improve statistical robustness and generalisability of their findings.
Reference
Huang T et al. Integrative analysis of oral microbiota and its gut transmission with host immunity in term pregnancy. npj Biofilms Microbiomes. 2026;DOI:10.1038/s41522-026-01009-4
Feature Image: H_Ko on Adobe Stock
