Researchers Say Kissing Can Transmit Depression and Anxiety

Researchers noted that kissing can transfer as many as 80 million bacteria during a single 10-second kiss. Among the bacterial strains identified in the study, four stood out: Clostridia, Veillonella, Bacillus, and Lachnospiraceae. These bacteria are not inherently harmful, but under certain conditions, they may disrupt the body's delicate balance and contribute to inflammatory responses or changes in neurotransmitter levels. The presence of these bacteria in the previously healthy partners corresponded with a measurable increase in symptoms of depression, anxiety, and sleep disturbances—especially among women.