Interactions between Perceived Stress and Microbial-Host Immune Components in Pregnancy

Background: Higher stress during pregnancy associates with negative outcomes and elevated inflammation. The gut microbiota reflects the environment, lifestyle, and the perinatal period. The gut microbiota, alongside host immune responses, has the potential to aid in identifying when stress is excessive. Methods: Two U.S. cohorts, of 84 pregnant individuals, composed of urban women of color and suburban white women, completed the Perceived Stress Scale-10 (PSS-10) and provided fecal and blood samples at two time points. Confirmatory Factor Analysis assessed the robustness of a two-factor PSS-10 (Emotional Distress and Self-Efficacy) in the two cohorts. Gut microbiota composition was measured by 16S rRNA amplicon sequencing and the immune system activity was assessed with a panel of 21 T-cell related cytokines and chemokines. Results: Emotional Distress levels were higher in the suburban compared to the urban cohort, but levels of Self-Efficacy were similar. Emotional Distress and Self-Efficacy levels were associated with distinct taxonomical signatures and the gut microbiota data improved the prediction of Self-Efficacy levels compared with models based on socio-demographic characteristics alone. Integration of self-reported symptoms, microbial and immune information revealed a possible mediation effect of Bacteroides uniformis between the immune system (through CXCL11) and Self-Efficacy. Conclusions: The study identified links between distinct taxonomical and immunological signatures with perceived stress. The data is congruent with a model where gut microbiome and immune factors may modulate neural plasticity resulting in increased Self-Efficacy during pregnancy. The predictive value of these peripheral markers merit further study.