Egert's harsh words stem for a study he and his team conducted that tested 14 regular household sponges for bacterial content. What they found was a horror-show, or more specifically, 362 different subspecies of bacteria packed tightly in an average sponge. Their findings, published in the journal Scientific Reports, present a cautionary tale for your kitchen sink. Why? It determined that there's about 82 billion bacteria festering within a cubic inch of space on your average sponge.
Yes, bacteria is everywhere -- including your own body -- and your sponge isn't likely to give you an infection, but that doesn't mean it can't. A bacteria called Moraxella osloensis tends to thrive on sponges and on human skin. Although it's largely responsible for the foul stench of your sponge and your dirty gym clothes, it can cause infections in people with weak immune systems, according to the study. So don't eat your sponge, no matter how appetizing the half-eaten remnants of your dinner might look.