Science Student Shares Top 5 Places Germs Grow the Fastest in Viral Videos

How many bacteria live on a subway seat? What about on your wallet? In your dog's mouth?

These are all questions that TikToker @the_lab_life1 endeavors to answer. By taking samples from everyday objects and growing the results, she creates videos that allow her followers to peer into the secret world of microbes that live around us.

@the_lab_life1, who goes by her initials, CM, is a Master's student at the University of Toronto. "My research is microbiology focused where I am studying the breast milk microbiome and the way it impacts infant health," she told Newsweek. "I am basically looking at the bacteria in healthy breast milk and linking it to the development of healthy infant microbiomes."

CM began making videos while working as a research assistant at the university lab to share funny day-to-day moments with her friends and co-workers. "I honestly didn't think anyone would ever see them," she said.

That all changed in October 2022, when CM shared a video of the different bacteria she was able to grow from her lab members' skin.

"Unexpectedly, this video blew up rather quickly and it kind of shocked me," CM said. "I got an overwhelming number of comments from people who found my content interesting yet funny which I was very excited about."

The video received over 3.1 million views, and since then CM has run a series of "what will grow" videos alongside her regular content. Like the bacteria, her audience has grown, and later videos in the series have been viewed over 20 million times.

"I find that people, including me, have a natural interest to see what they normally can't, so I thought why not try to show them?," CM said. "As I used to be what one would call a 'germaphobe,' doing these videos actually makes me less scared.

"Everything will always have some sort of microbiome on it, but I have learned to accept that. It's like the bacteria have their own little lives and cities, but instead it's on an apple."

It is important to remember here that not all bacteria are bad, and some are actually essential to our health. "What grows shouldn't scare anyone, as most of it is just commonly found, friendly bacteria that a healthy immune system can easily clear," CM said.

To shed light on these microscopic metropolises, CM collects and cultures the bacteria using a standard protocol: "Once I swab something using a sterile cotton tip applicator, I will spread it onto a nutrient agar plate which supports bacterial growth," she said.

"I make a lawn on the plate, where I basically create a crosshatch design so I know that the entire plate is covered. I will then put the plate in an incubator which is at a specific temperature to allow for growth. It stays in the incubator for usually 24 to 48 hours and then I pull it out and see all the cool bacteria that grow, or lack thereof."

Some of the results have been pretty surprising. "Usually, I have a general idea of what might grow based on the surface I am swabbing, so I can genuinely say that the subway seat was the most shocking discovery," CM said. "I thought it would grow a wide array of bacteria, some even being pathogenic, but I was pleasantly surprised that almost nothing grew on the plate.

She added that the conditions used for the plates might not be suitable for all types of bacteria, but the experiments still give you a rough idea of what microbes might be present on a particular surface.

As a microbiologist, CM said that nothing really grosses her out any more when it comes to bacteria. But what have been her top five most disgusting discoveries?

1. Lab Member's Shoe

   "She is a dental clinician, so she is stepping on a lot of different organisms all day long, but the plate that resulted really did gross me out."

2. Boyfriend's Dog's Mouth

   "One that is definitely up there in grossness level, is when I swabbed the mouth of my boyfriend's dog. While extremely cute, as you can imagine, the dog doesn't have the best smelling breath, so I knew that the bacteria that would grow would be similar in scent...Hopefully, no one is reading this while eating lunch."

   @the_lab_life1

   A special thanks to Ziggy, Drama, and Rafiki! #fyp #foryoupage #lab #science

   ♬ Electric Love - BØRNS

3. Boss's Wallet

   "I thought it was quite surprising how much bacteria grew from my boss's wallet....the bacteria was just so thick, dense, and raised."

4. Water Fountain

   "While it wasn't gross to me, it did grow a lot of bacteria. This was kind of expected though, because bacteria thrive in the damp conditions of a water fountain."

5. Public Toilet

   "Swabbing a public toilet in itself is quite gross, so I definitely didn't love that one. Considering that it was from a toilet, the bacteria that grew were not very icky, but the plate did grow a lot of different bacteria, which is always fun to see because of all the different colors and shapes."

CM said that the response to her channel has been extremely positive. "I love that I am able to interact with other science fanatics while also being able to speak with parents who have children that love my videos. It makes me very happy knowing that my videos not only educate but bring joy to so many people.

"I hope that people can just see how fun and exciting science can be [...] I also hope it can show prospering students that there are so many different opportunities where they can study science or work in the scientific world."