In many cultures, taking your shoes off before entering someone’s home is not only common courtesy, it’s an expected social norm. Bare feet are expected, and not taking off your shoes could be considered rude or inconsiderate. In most western cultures, however, shoes on inside the home is still the norm, even though there are important reasons to consider removing them.
When you consider that the purpose of shoes is to protect your feet and keep them from getting dirty, it only makes sense that you wouldn’t need them indoors. And when you take into account all the things the bottoms of our shoes come into contact with during a normal day, the argument for ditching your shoes at the door becomes clear.
Shoes may bring high levels of bacteria into your home.
Everyday we walk across surfaces that have been contaminated by bacteria, like public bathroom floors, and outdoors where birds and other animals defecate. A at the University of Arizona suggests that the bottoms of shoes average 421,000 individual units of bacteria. And when those contaminated shoes were used to walk across clean, uncontaminated floor tiles, the rate of transference was almost 90 percent. Bacterial species like E. Coli, which can cause severe intestinal distress and other severe illnesses and klebsiella pneumoniae, a causative agent of bacterial pneumonia, were both commonly found on shoes.