Prenatal oral microbiome associated with mother’s stress, mental health

Key takeaways:

• The oral microbiome of pregnant women differed among those with high vs. low stress or anxiety.
• The data suggest targeted probiotic treatment might improve mental health.

During pregnancy, various aspects of the oral microbiome were associated with stress and mental health, differing from known ties between the gut microbiome and mental health, researchers reported in BMJ Mental Health.

“Our findings have significant clinical implications for both diagnosis and treatment,” Ann M. Alex, MD, research assistant professor at Texas A&M University, told Healio. “Saliva sampling as a noninvasive method could serve as a valuable tool for monitoring maternal psychological wellbeing during pregnancy. On the treatment front, interventions could expand to targeting the oral microbiome in addition to the gut microbiome. This approach may involve dietary modifications, recommendations to enhance oral health and the use of probiotics to support mothers experiencing high life stress and poor mental health.”

Alex and colleagues measured microbes in saliva obtained from 224 women in their second trimester of pregnancy participating in the Michigan Prenatal Stress Study. All participants self-rated state and trait anxiety and were categorized as having high (n = 96) and low (n = 126) state anxiety symptoms and high (n = 122) and low (n = 99) trait anxiety symptoms. Participants also self-rated depression and PTSD and were categorized into high (n = 104) and low (n = 118) depression symptom groups and high (n = 75) and low (n = 142) PTSD symptom groups.

The most abundant families of the oral microbiome observed were Streptococcaceae (26.2%), Prevotellaceae (20%) and Veillonellaceae (12%).

Overall, pregnant women in the high trait anxiety or depression symptom groups had higher oral alpha diversity, which indicated higher species richness in samples. Women with high and low PTSD symptoms had different beta diversity, which indicated differences in community composition. Researchers observed differently abundant microbes in pregnant women with high vs. low life stress, anxiety, depression and PTSD, with affected microbes mainly differing by symptom type.

Pregnant women with high recent life stress had a higher abundance of members of the phylum Proteobacteria, those with high depression symptoms had a higher abundance of Spirochaetes and those with high trait anxiety and/or depression symptoms had a higher abundance of Firmicutes.

In addition, pregnant women with high trait or state anxiety, or high depression symptoms, had a higher abundance of the genus Dialister and those with higher trait anxiety, depression or PTSD had a higher abundance of the genus Eikenella.

“Two key findings of this study stand out,” Alex told Healio. “First, the association between oral microbiome and maternal mental health measures varied depending on the specific condition — whether life stress, anxiety, depression or PTSD was examined. Second, these associations in pregnant women were different from those observed in gut microbiome or in non-pregnant individuals. These suggest a unique signature of mental health status on the oral microbiome.”

Alex said the next step is to conduct longitudinal studies to explore how the relationship between the oral microbiome and mental health evolves throughout pregnancy and into the postpartum period.

“Incorporating a multiomics approach that will combine oral and gut metagenomics, metabolomics and neuroimaging will provide a more comprehensive understanding of the impact of microbiomes on maternal mental health,” Alex told Healio.

For more information:

Ann M. Alex, MD, can be reached at allexann@msu.edu.