Ewww...What is that smell? Were my socks washed in skunk juice? Did my feet turn into moldy cheese I don’t think so. It is my stinky sneakers.
I hold my nose when I take off my sneakers. My mom holds her nose too. My dog sniffs and quivers with delight. Why are my sneakers so smelly?
My stinky sneakers were not dropped in the garbage. They did not come from a manure factory. My sneakers stink because they have tiny creatures called bacteria (back-teer-ee-ah) living in them. It is not the sneakers that smell, it is the bacteria living in them. More precisely, it is not the bacteria in my sneakers that smell, it is their farts.
Your old shoes probably have smelly bacteria too. But no matter how hard you or I look in our shoes, we will not see the bacteria. They are too small. We cannot see everything that is real.
Bacteria don’t just live in my sneakers… They live all over me, all over my body, inside and out. Bacteria live everywhere. On animals, on plants, in the air, in the soil, in the water. Bacteria live deep in the ground, on the ocean floor, on the top of Mount Everest, in the clouds, in the Antarctic ice.
The bacteria that live on my body are body bacteria. They like it warm, the temperature of me. Not all bacteria living on me are stinky. Some of them keep me healthy. I need them to help me make vitamins and keep my skin clean. But a few of the bacteria that live on my body can make me sick. Sometimes, my throat gets sore because too many bacteria are growing in my mouth.
Most bacteria just hang around, living on me like I live on the Earth. The stinky bacteria living in my sneakers are like that. There is more than one kind of bacteria living in my stinky sneakers. They have big names like Staphylococcus (Staff – ee – low –cock – us) and Propionibacteria (Pro – pee – on –ee – back – teer – ee – a). Stahylococcus are very small, and are shaped like a marble. Propionibacteria are shaped like jellybeans. These kinds of bacteria like to live where it is warm and dark. My sneakers are a perfect home.
My sneakers have something else that these bacteria love..lots of sweat to eat. Feet make a lot of sweat. Most people’s feet make more than a cup of sweat, every day. The sweat my feet makes soaks into my socks and into my sneakers. Sweat is mostly water, but there is also a little bit of salt and a little bit of sugar. Sneaker bacteria eat this salt and this sugar. It is their favorite food.
The more sweat in my sneakers, the more bacteria food. The bacteria grow and make even more bacteria. If there was a straight line of bacteria from my toe to my heel, there would be sixty thousand bacteria in a row. Lots of sweat makes crowds of bacteria. My sneakers are like a giant bacteria concert, like the Superbowl, or Times Square on New Year’s Eve.
My sweat does not smell. But when the bacteria in my stinky sneakers eat it, they sure leave behind smells when they finish dinner. In a way, it is like lots of minuscule bacteria farts. Phew!
Scientists are trying to grow a new kind of bacteria that eats sweat but does not make bad smells. This kind of bacteria would live in sneakers and clothes and eat up all the sweat and dirt. My sneakers would stay clean and never need to be washed. My mom says these scientists should hurry up.
Stinky sneakers mean that I have been playing and running. Stinky sneakers mean that I have been exercising and staying healthy. Stinky sneakers give my bacteria a place to live and food to eat.
When I get home, I take my stinky sneakers off. And I put my smelly socks in the laundry basket. And then I do the stink test. I lift my leg in the air, point my toes at my sister and say, “smell my feet.” If she holds her nose or runs away, my feet are stinky too. And then I know…
...it is time to take a bath.