EMERGING research highlights the oral microbiome’s potential role in maternal mental health, suggesting an oral-brain-behaviour axis distinct from the gut-brain axis.
A study involving 224 pregnant women in their second trimester (mean 17±2 weeks) examined associations between oral microbes and mental health symptoms, including stress, anxiety, depression, and post-traumatic stress disorder (PTSD). Participants were oversampled for stress, and saliva samples were analysed to assess microbial diversity and composition. Covariates such as age, income, substance use, dental issues, and physical health problems were considered.
The results revealed significant associations between the oral microbiome and mental health symptoms. Women with high trait anxiety or depression symptoms demonstrated greater oral alpha diversity, indicating a higher richness of microbial species. Differences in beta diversity, reflecting overall microbial community composition, were observed between groups with high and low PTSD symptoms.
Linear discriminant analysis identified distinct microbial profiles associated with elevated stress, anxiety, depression, and PTSD. For instance, Proteobacteria were more abundant in women experiencing high recent life stress, while Spirochaetes was elevated in those with high depression symptoms. Similarly, members of the Firmicutes phylum were associated with high trait anxiety and depression. The genus Dialister, previously found at lower levels in the gut of depressed non-pregnant individuals, was more abundant in women with high anxiety or depression, and Eikenella levels were elevated in those with high anxiety, depression, or PTSD.
These findings demonstrate that the oral microbiome is intricately linked to mental health in pregnant women, differing from patterns observed in the gut or in non-pregnant individuals. Understanding these relationships may open avenues for developing microbial-based interventions to support maternal psychological well-being.
Reference
Alex AM et al. Stress and mental health symptoms in early pregnancy are associated with the oral microbiome. BMJ Ment Health. 2024;27(1):e301100.
