Future applications for polar explorers and deep-sea divers might include a probiotic cream applied to the skin. This innovation aims to provide a novel defense against frostbite and hypothermia. The optimism stems from scientists successfully genetically engineering bacteria, commonly found on human skin, to detect temperature changes and subsequently generate more heat when necessary.
Harris Wang, a researcher at Columbia University in New York who was not involved in the study, described the work as highly creative. He noted its potential to significantly influence a person’s susceptibility to frostbite. Wang highlighted broad potential uses, ranging from staying warm during winter and preventing frostbite on expeditions to critical applications in deep-water diving where heat generation is paramount.
Genetic Modification of Cutibacterium acnes
A team of researchers, led by Guillermo Nevot Sánchez at Pompeu Fabra University in Barcelona, Spain, focused on a strain of the bacterium Cutibacterium acnes. This microbe is one of the most prevalent inhabitants of healthy skin. Using CRISPR gene-editing technology, they modified the bacteria to produce twice their normal heat output. This was achieved by adjusting the levels of the arcC protein, which plays a role in energy production within the bacterium.
In a separate experiment with another batch of C. acnes, the same CRISPR technology was employed to alter the expression of heat-sensitive genes. This modification enabled the microbes to identify temperatures exceeding 32 degrees Celsius. Upon detecting such temperatures, the bacteria signaled this change using a fluorescent marker.
Proof-of-Concept and Future Challenges
Nevot Sánchez stated that these combined findings represent the first demonstration that skin bacteria can be engineered to increase heat production in response to temperature fluctuations. The next critical step for the research team involves integrating both of these engineered capabilities into a single bacterial strain. Furthermore, they must prove that these modified bacteria can reliably detect a dangerous drop in temperature, rather than merely responding to an increase.
The research team has reportedly conducted preliminary experiments, not yet published, which indicate that C. acnes strains can maintain viability when incorporated into a cream formulation. Nevot Sánchez presented these findings at the Synthetic Biology for Health and Sustainability conference. He suggested the possibility of developing a probiotic cream that could be applied widely across the body, potentially before entering cold environments, as a preventative measure against hypothermia. He also noted its potential benefit for individuals living in cold climates without adequate heating.
However, further investigation is required to ascertain the extent to which such a cream effectively heats human skin. Wang emphasized the need for laboratory tests on skin samples and subsequent trials on mice before any human testing can commence. Nevot Sánchez also identified the crucial development of methods to deactivate the bacteria when intended, perhaps through the application of a secondary cream. This control mechanism would be vital to mitigate potential adverse effects, such as overheating.