A recent study found that the floor of the New York subway contained nearly 600 different types of microbes. However while some could give people food poisoning or even meningitis, the vast majority were completely harmless.
In fact, some scientists say they could even be good for people, especially children.
Studies into the ‘hygiene hypothesis’ claim exposure to bacteria and other germs at a young age can actually boost and ‘train’ a person’s immune system to deal with infections as they get older.
Many mums ars themselves with hand sanitiser and disinfectant to protect their children, but since every surface in the world is covered in bacteria, this can be a futile exercise. According to Chris Mason, a Weill Cornell Medical College geneticist, the idea that things can be "perfectly clean" is a myth and humans need bacteria to live.
“We tend to think of our homes and personal environments as these pristine places, and public ones as dirty and infested with bacteria. But you should really think of yourself as a rabbit who gets to hop between two forests."
The human body already has thousands of different species of bacteria living inside and on it from digestive bacteria in our intestines to the microbes hanging out on our skin. Many scientists will even argue that bacteria is essential for a properly functioning body.
In fact, there is research that suggests the ‘hygiene hypothesis’ could explain why children who grow up around animals or in rural areas have been observed as less likely to develop conditions like asthma. This is why geneticist Chris Mason isn't afraid to let his own little girl get muddy or take public transport.
"I would advise any new parent to roll their child on the floor of the New York subway,"