Researchers Say Kissing Can Transmit Depression and Anxiety

Interestingly, this concept is consistent with previous research showing that couples often "sync up" in various biological ways. Studies have demonstrated that long-term partners can develop similar heart rates, sleeping patterns, and even hormonal cycles over time. This phenomenon, known as "physiological synchrony," is believed to be a byproduct of emotional closeness and daily cohabitation. The idea that microbiota may also synchronize between partners is both logical and intriguing—especially if such synchronization influences mental health.