Imagine for a moment that you had microscopic vision. You would see an entirely different world within the world we currently perceive: a diverse, bustling metropolis full of activity.
Millions of microscopic species are constantly interacting, communicating, sharing and competing all around us. Our bodies are vibrant natural theatres hosting trillions of bacteria, viruses, fungi and other microorganisms. We are deeply connected to these microbes in a biological and evolutionary sense – and there is growing recognition that this invisible biodiversity plays a fundamental role in our health, and also in the health of our ecosystems.
But a threat is spreading: “germaphobia”, or the fear of microbes. This phenomenon could be detrimental to our health, and our ecosystems, by encouraging people to avoid the natural world. Our new research suggests that basic microbial literacy and nature exposure may be important in reducing and preventing these attitudes.
After all, a whopping 8% of our own human genome was acquired “horizontally” through viral infections, not inherited “vertically” from our parents’ DNA. Even the human mitochondria cells that provide much of the human body’s chemical energy are thought to have evolved from a bacterium millions of years ago.
Microbes educate our immune systems by stimulating tiny armies of memory cells that protect us from disease and create chemicals that our bodies need to control inflammation and promote good mental health. Microbes also play key roles in plant health, nutrient cycles (like the nitrogen cycle) and regulating the climate.
Let’s go back to the dawn of germ theory during the 19th century. It was a remarkable development in human thinking when scientists understood that microbes were responsible for a variety of human illnesses. This knowledge has undoubtedly saved millions of lives in the decades since.
However, knowing that some microbes – actually far fewer than 1% – cause human diseases, has led many people to fear and loathe all microbes. It is likely that this germaphobia has been compounded by decades of advertising campaigns, such as those selling household detergents, that have created negative perceptions of microbes as a whole.
The result? Mass sterilisation of surfaces, avoidance of natural dirt and reduced human contact with biodiversity. This could be contributing not only to a loss of appreciation for the vital, invisible universe around us, but also to an explosion of human immune-related disorders. Whilst targeted hygiene, for example around food and toilets, remains essential, attempting total elimination of dirt from our lives is where the danger lies.
In our recent study, my colleagues Professor Anna Jorgensen, Dr Ross Cameron and I at the University of Sheffield set out to understand whether there was a relationship between people’s engagement with nature and attitudes towards microbes. We also investigated whether basic “microbial literacy”, such as the ability to correctly identify different microbial groups, might influence these attitudes. We developed an online questionnaire and received well over 1,000 responses.
We found that people who showed more positive attitudes towards microbes spent significantly more time in nature per week and spent significantly longer in nature per visit. These results suggest that germaphobia-related attitudes may reduce people’s desire to spend time in nature. Or on the flipside, it could mean that spending time in nature increases positive attitudes towards microbes.
This points to a possible strategy to help challenge the negative consequences of germaphobia – spending more time engaging with nature. The benefits of doing so could include improving immune function via exposure to environmental microbes which help regulate our innate immune system (fighting pathogens before they cause infection) and adaptive immune system (stimulating memory cells).
There are a range of advantages associated with engaging with nature which make this strategy all the more appealing. For example, it can reduce stress and anxiety while promoting social cohesion and a sense of connection.
We found that microbial literacy was also associated with positive attitudes towards microbes. This suggests that having a basic understanding of microbes may encourage people to view them in a more positive light.
This could be very powerful. For example, teaching children about the different ways microbes support individual and planetary health could play a role in reducing germaphobia in the future by promoting appreciation for these essential lifeforms.
We also found that people who identified viruses as being microbes had a significantly more negative attitude towards microbes in general. This may be the result of the recent COVID-19 pandemic, as people understandably fear the SARS-CoV-2 virus.
However, there is a risk that all microbes might be unfairly tarnished with the same brush. Bacteria, archaea, algae, fungi and protozoans – even viruses – all have key roles in our ecosystems.
We believe that a greater emphasis on microbial literacy and promoting engagement with nature could help enhance human health and promote more positive, constructive attitudes towards the foundations of our ecosystems – the microorganisms themselves.