A quick dip in the ocean is hard to beat on a hot day, but a new study shows that ocean bacteria can colonize your skin surprisingly fast – and some types of it can be quite dangerous.
Researchers say that just 10 minutes of swimming in the ocean is enough to see your skin covered in bacteria. In a study, people who weren’t wearing sunscreen and only swam in the ocean infrequently were asked to swim on a California beach for just 10 minutes. The participants couldn’t have bathed within the last six hours, nor could they have taken any antibiotics in the last six months. After comparing swabs taken before and after the swim from the skin on the back of the participants’ calves, the researchers discovered they were covered in a common ocean bacterium that is typically found in saltwater known as Vibrio.
Although not all Vibrio strains are bad, some do cause diseases, and it can increase your overall risk of infection by disturbing the skin’s microbiome in a way that makes it easier for bacteria to penetrate. This microbiome is what protects us against germs, and the ocean water seems to change the diversity and composition of it. In fact, while each volunteer’s skin microbiome was distinctive prior to the swim, they actually became quite similar to one another immediately afterward because of the degree of alteration the bacteria caused.
Certain pathogenic Vibrio species can cause illnesses like cholera or flesh-eating infections. Vibriosis leads to 80,000 illnesses and 100 deaths in the U.S. each year, and most infections take place when the water temperatures are warmer. The researchers also noted that the bacteria seemed drawn to people’s skin as the proportion found on their skin was higher than that found in the surrounding ocean water, which they also tested.
Although the researchers emphasized that their study is still a work in progress, it may provide some clues as to why people who swim in the ocean regularly are more likely to come down with ear infections and stomach aches. While most infections people get from swimming in the ocean are caused by feces entering the body, the researchers believe that ocean bacteria in general is making it easier for various types of bacteria to get in through the skin.
Is pollution behind this alarming problem?
If you grew up near the beach, you probably remember how amazing the salty ocean water was for all manner of skin complaints. If your legs or feet had insect bites or itchiness, the problem was usually a lot better after spending the morning at the beach. So what has changed?
One big culprit could be pollution, particularly plastic pollution. A study carried out by the National University of Singapore shows that microplastics that pollute our oceans are harboring pathogenic microbial communities.
One of the bacterial strains they found in microplastic samples taken across several types of beaches was Vibrio. Not only can Vibrio cause life-threatening infections in humans, but it can also be toxic to marine species like brine shrimp and black tiger prawn. At every site studied, they also found the strain V. fluvialis, which is an emerging pathogen that can survive for extended periods of time in sea water and is able to resist antibiotics.
This is just one example of how our mistreatment of the environment could prove to be our undoing. Plastic pollution in the planet’s water continues to be a huge problem, and it’s only a matter of time before it’s too dangerous to go swimming at the beach if we don’t take this issue seriously.
Sources for this article include:
- Drugs can turn your gut microbiome against you – and even kill you
- Study: The health of your gut microbiome influences muscle strength
- Colorectal cancer is a microbial disease: Changes in the gut microbiome can be used for early detection
- It starts in the gut: Stress and autoimmune disease can be traced back to your microbiome