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.

“No extant studies of the oral microbiome and mental health have involved pregnant or postpartum samples. Research with other groups indicates that levels of a number of specific bacterial taxa in saliva obtained from adolescents and young adults differ between those with high anxiety, depression symptoms or suicide ideation compared with unaffected individuals,” Ann M. Alex, MD, research assistant professor at Texas A&M University, and colleagues wrote in BMJ Mental Health. “Furthermore, adults with high psychological distress ... differed from individuals with low psychological distress in the alpha and beta diversities of their oral microbiome and levels of numerous individual microbes.”

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.

“Successful targeting of the gut microbiome with probiotic treatment to improve maternal mental health could be extended in future studies to target oral cavity microbes through dietary changes, making recommendations for improving oral health, and probiotic treatments that might benefit mothers struggling with high life stress and poor mental health,” the researchers wrote.