Overview

• A study of 1,740 newlywed couples in Iran found that oral microbiota transmission partially mediates shared depression, anxiety, and sleep disturbances over six months.
• Healthy spouses living with partners experiencing depression and anxiety developed similar mental health symptoms and microbiome profiles.
• Specific bacterial taxa, including Clostridia, Veillonella, Bacillus, and Lachnospiraceae, were more abundant in couples where one partner had mental health issues.
• Changes in oral microbiota correlated with altered salivary cortisol levels, suggesting a link between microbial shifts and stress responses.
• Women were identified as more susceptible to microbiota transmission, exhibiting more pronounced changes in both mental health and oral microbiome composition.