Bacteria are literally everywhere. They can be found in the ground, on the subway, in and on your body. Humans are mostly made up of bacteria. There are more of them than there are of us, as for every our cell, there are ten bacterial cells. The greatest number of bacteria in our bodies can be found in the gut, which isn’t at all surprising.
There has been a lot of research lately about the microbiome, the ecosystem of bacteria that lives in and on us. One small study published in the journal Science found out that other bacteria-laden areas of the body include your palms, feet, and the areas behind your knees. But, the greatest diversity of bacteria on your body can be found on your forearms.
However, bacteria can’t be found only in and on our bodies. They are around our bodies as well. We actually walk with a cloud of bacteria everywhere we go. In a study published in the journal Peer J, the researchers captured the air surrounding the participants of this study. They had the participants sit in boxes for four hours, and then they measured the air around them. They found out they could identify thousands of types of bacterial DNA and could tell whether the person was male or female. So, basically, you can get someone else’s microbes even when you’re just standing next to them.
So, once bacteria leave us, where do they go? Well, places that have the most bacteria tend to be those like public transit. One recent, really cool study was a massive undertaking by researchers at Weill Cornell Medical College. They swabbed thousands of surfaces of the New York City subway system. A system that sees nearly 5.5 million people per day passing through its stations and trains. Their findings were published in the journal Cell Systems. In total, they found DNA from more than 15 thousand different life forms. Almost half of the DNA belonged to bacteria.
However, most of the bacteria they found is harmless and only 12% were linked to diseases. They can be found at home as well. There’s millions and millions of microbes in nearly every part of our homes. And one study published in the journal Science analyzed the homes of seven families over the course of a few weeks. What they found was something surprising. The people involved in the study seemed to make the bacteria. In other words, when three of the families moved, it only took one day for their new house to look like their old house, microbially at least.
Bathrooms can be pretty gross. But not as gross as you would think. It turns out your bathroom is dominated by bacteria from your skin, which is something definitely unexpected. Bacteria like Roseburia, Lactobacillus, and Anaerococcus are present in restrooms. But only for a short period of time, as bathrooms are too cold, too dry, and oxygen-rich to support the growth of these kinds of bacteria. Instead, 68-98 percent of the bacteria the researchers found came from our skin and from outdoors. So, the germiest place in your home isn’t the toilet.
One study published in the Journal of Applied Microbiology found that it’s the kitchen. Especially the areas that remain moist like the kitchen sink, which gets touched a lot. The study found that the sink can have nearly 100,000 bacteria per square centimeter whereas the toilet has only about 100. And let’s not even mention the dish sponge, as they have the highest concentration of bacteria of any place in the home.
But bacteria get a bad reputation these days. In reality, it is not all that bad. In fact, some of them are pretty good for us and are indispensable for our health. One research shows that being exposed to more bacteria actually bolsters our immune systems. There are some theories out there that say we’re actually too clean, which leads to modern diseases like asthma. And it is just as much a part of us as anything else. So, although if I were you, I’d toss out the dish sponge right now, a fine balance of bacteria seems to be just what a doctor would order. But the dish sponge is not the only thing that’s covered with bacteria, your cell phone is not what it seems to be as well.