POTION: promoting social interaction through emotional body odors

Dr Eliasson and colleagues first introduced the POTION project in a BMC On Medicine blog. 

The POTION project aims at understanding how olfaction (our sense of smell) affects human social interactions, and to use that knowledge to develop tools promoting healthy relationships. While many animals use chemical signals for social communication, human studies have tended to focus on sight and sound. However, recent research shows that humans can ‘sense’ emotions such as fear and happiness, not only through visual and auditory stimuli but also through smell. Emotions are conveyed through smell via chemosignals, found in human sweat, which can play a role in communication and social functions. POTION aims to explore how olfactory cues can influence relationships and well-being by delving into the chemistry behind human chemosignals, specifically the emotion of fear.  However, even though several studies have shown that chemosignals, extracted from human sweat, can be used to communicate different emotional states, it is important to highlight that this reaction occurs unconsciously and can be measured by, for instance, changes in facial muscles or eye movements.

Building on existing literature on olfactory processing, previous POTION project studies registered on the ISRCTN registry (ISRCTN98675422 and ISRCTN64408867) showed that individuals with social anxiety symptoms who underwent a mindfulness meditation intervention displayed a steeper reduction in anxiety symptoms when exposed to human chemosignals, compared to those undergoing the same mindfulness intervention in clean air.

Moving forward: A randomized controlled trial of synthetic sweat

The previous POTION studies were conducted using sweat samples collected from healthy volunteers. However, as the collection of human sweat can be both time-consuming and costly, the next step of the project concerns testing the therapeutic effect of artificially synthesized chemosignals.

To this aim, our POTION partners at the    University of Pisa have identified and isolated chemical compounds thought to be linked with human fear chemosignals - the emotion that produced the strongest therapeutic effect in the clinical studies already carried out by our team (discussed in the prior blog). These compounds have been added to a reference sweat solution that was created based on artificial apocrine sweat modified with a subtractive isolation method to obtain a chemical profile comparable to the sweat samples collected during a relaxed state.

The final product is a liquid solution of “synthetic sweat”, that will be used in the current study (ISRCTN11342305) and delivered to volunteers through a newly developed odor delivery machine: the so-called POTION delivery system (PDS). The two-arm RCT will take place at the University of Padua and the study intervention will be conducted over two consecutive days. Like the previous pilot study, the target group will be women aged 18 to 35 who score 30 or above on the Liebowitz Social Anxiety Scale (LSAS). After recruitment and collection of informed consent, subjects will be randomly allocated to an intervention group (mindfulness + fear odor) or an active control group (mindfulness + clean air) in which they will remain for the duration of the trial. More specifically the intervention consists of 25 minutes of mindfulness meditation, either while exposed to fear odor delivered by the PDS, or clean air. The main outcome measure will be changes in symptoms of anxiety, but other variables, such as electrodermal activity and heart rate will also be assessed.

Potential impact

In addition to the general impact of the POTION project presented in the previous blog, several advantages can be drawn from developing synthetic sweat.

Firstly, synthetic sweat enables precise control over the composition of chemical compounds, ensuring consistency across experiments. This standardization is crucial for reliable research outcomes, eliminating variations that may arise from individual differences in natural sweat. In addition, synthetic sweat can be manufactured in controlled laboratory conditions, which is essential for maintaining the integrity of the study and minimizing the risk of contamination or undesirable variables.

Moreover, creating synthetic sweat eliminates the need to collect bodily fluids from human donors, addressing ethical concerns related to privacy, and potential discomfort associated with the sweat collection process.

Finally, developing synthetic sweat can be more cost-effective in the long run compared to the effort and resources required to collect, store, and process sweat from multiple human donors. It can also be readily produced, making it more accessible for researchers and larger-scale experiments.

More information

Please visit the POTION website for more information. Or follow the project on social media (Twitter).

Funding

The POTION project and the study are funded by the European Commission H2020 Framework Program, Grant No. 824153.