There are many behaviors that humans exhibit, especially in today day and age, that contribute to the reduction of exposure to microbes. One of which is self isolation, which many people are doing today due to COVID-19. If not self isolation, many people are at least attempting to limit the number of people that they interact with. This leads to a reduction of exposure to microbes because just as people are diverse, so are the microbes that they carry, and as we see fewer and fewer people, we also see fewer and fewer microbes.
Another example of this phenomenon is hand washing and use of antibacterial agents such as hand sanitizer. Although your skin is still exposed to external microbes, other systems such as the mouth and nose will see less exposure to microbes as a result of this behavior. This is another behavior that has been increased due to the prevalence of COVID-19.
A final example of a human behavior that reduces exposure to microbes is the decision to work at home. Many people are working from home because of COVID, but it is not some new idea that was brought about because of the virus. People have been working from home more and more as the internet and related services have expanded, resulting in having fewer coworkers, or at least seeing them, and thus a lessening in the exposure to microbes.
