A new study has found that changes in the oral microbiome during pregnancy are linked to shifts in the maternal immune system.
Researchers analyzed 25 pregnant women at term and 25 non-pregnant women, profiling oral and gut bacteria, salivary metabolites, and immune cells.
They found that bacterial species such as Streptococcus anginosus and Prevotella denticola were associated with increases in natural killer cells. Other oral bacteria were linked to a specific subset of these immune cells.
However, the study suggests that salivary fatty acids do not appear to mediate the connection between oral bacteria and systemic immune changes.
Evidence also suggests that certain microbes may travel from the mouth to the gut, influencing the immune response further. These findings could help explain how the immune system adapts during pregnancy.
Researchers call for larger, more diverse studies to confirm these results.