Oral microbiota dysbiosis and altered salivary cortisol levels have been linked to depression and anxiety. Given that bacterial transmission can occur between spouses, this study aimed to investigate whether the transmission of oral microbiota between newlywed couples mediates symptoms of depression and anxiety.
Methods
Validated Persian versions of the Pittsburgh Sleep Quality Index, Beck Depression Inventory-II, and Beck Anxiety Inventory were administered to 1,740 couples who had been married for six months. The researchers compared 268 healthy control spouses with 268 affected cases in a cross-sectional study. Data were analyzed using appropriate statistical methods.
Results
After six months, healthy spouses married to an insomniac with the depression-anxiety (DA) phenotype scored significantly higher on the Pittsburgh Sleep Quality Index, Beck Depression Inventory-II, and Beck Anxiety Inventory compared to their baseline scores. This indicates that their sleep quality, depression, and anxiety scores became more similar to those of their affected spouses. Additionally, the composition of their oral microbiota changed significantly, becoming increasingly similar to that of their spouses. Specifically, in couples where one partner had the DA phenotype, the oral microbiota of the healthy spouse mirrored that of the affected partner (p < 0.001). These microbial changes correlated with alterations in salivary cortisol levels as well as depression and anxiety scores. Linear discriminant analysis revealed that the relative abundances of Clostridia, Veillonella, Bacillus, and Lachnospiraceae were significantly higher in insomniacs with the DA phenotype compared to healthy controls (p < 0.001).
Conclusions
The transmission of oral microbiota plays a partial role in mediating depression and anxiety among couples. Since this study is associational, further research is needed to establish whether this association is causal. If it is determined that this association is indeed causal, it could have significant implications for contemporary research. We propose that, within the framework of diagnostic, predictive, preventive, and personalized medicine, the practical and theoretical implications of this study may enhance our understanding of various aspects of microbiota-host interactions.
Full text:
https://www.xiahepublishing.com/2472-0712/ERHM-2025-00013
The study was recently published in the Exploratory Research and Hypothesis in Medicine .
Exploratory Research and Hypothesis in Medicine (ERHM) publishes original exploratory research articles and state-of-the-art reviews that focus on novel findings and the most recent scientific advances that support new hypotheses in medicine. The journal accepts a wide range of topics, including innovative diagnostic and therapeutic modalities as well as insightful theories related to the practice of medicine. The exploratory research published in ERHM does not necessarily need to be comprehensive and conclusive, but the study design must be solid, the methodologies must be reliable, the results must be true, and the hypothesis must be rational and justifiable with evidence.
