Pregnant individuals diagnosed with inflammatory bowel disease (IBD) demonstrate elevated levels of pro-inflammatory immune molecules in their vaginal mucosa compared to their healthy peers. This finding stems from research conducted by Ana Maldonado-Contreras and colleagues at the University of Massachusetts Chan Medical School, published in the journal PLOS One. The study highlights the increased risk of adverse pregnancy outcomes faced by those with IBD, including preterm birth.
The study involved a cohort of 48 pregnant individuals in their third trimester, comprising 23 with IBD—18 diagnosed with Crohn’s disease and five with ulcerative colitis—and 25 healthy participants. Over half of the individuals with IBD were in remission at the time of the study. Researchers collected vaginal swabs and conducted three nutrition assessments to evaluate dietary intake.
Results indicated that while participants with IBD had similar bacterial profiles in the vaginal mucosa as their healthy counterparts, they exhibited significantly higher levels of pro-inflammatory cytokines, particularly IL-6, IL-8, and IL-17. Conversely, they had lower levels of the immune-regulating cytokine IFN-γ and the anti-inflammatory cytokine IL-4.
Impact of Diet on Inflammation
Interestingly, the study also explored the relationship between dietary habits and inflammatory markers. Among all participants, those maintaining a higher intake of vegetables and a lower consumption of added sugars showed increased levels of the beneficial microbe Lactobacillus crispatus. This dietary pattern was associated with lower levels of the pro-inflammatory cytokine IFN-γ and elevated levels of IL-4, suggesting that nutrition plays a critical role in modulating inflammation during pregnancy.
Despite these insights, the study’s limitations include a modest sample size and the exclusive focus on the third trimester, which restricts the ability to assess fluctuations in inflammation throughout the entirety of pregnancy.
The authors emphasize that the presence of a pro-inflammatory vaginal environment in pregnant individuals with IBD, even when in remission, may elucidate the heightened risk of preterm birth associated with this condition. This research underscores the importance of monitoring inflammation in this vulnerable population, potentially guiding future dietary recommendations to improve pregnancy outcomes.
The study, titled “Association of vaginal IL-4, IL-6, IL-8, IL-17, IFN-γ, and dietary intake with IBD status and vaginal microbiota in pregnant individuals,” is available in PLOS One as of 2026 and can be accessed via DOI: 10.1371/journal.pone.0335178.
