Even if you’ve never heard of it, you’ve almost certainly come across triclosan. A highly effective antibacterial and antifungal ingredient, triclosan is found in all kinds of toothpastes, hand sanitizers, deodorants, mouthwashes, detergents, cleaning supplies—if you use household products, you’re interacting with triclosan every day.
So it’s worrying that a new study, published in Science Translation Medicine on Wednesday, suggests that triclosan exposure could increase rates of colitis and colon cancer.
It all comes down to what happens to your gut microbiome. It seems that triclosan devastated the diversity of bacteria found in the gut microbiome of the mice, and in particular killed off populations of Bifidobacterium, a “good” bacteria.
Triclosan is used in thousands of different consumer products. Although the FDA banned triclosan in hand soaps and body washes in 2016, citing safety concerns and skepticism that triclosan worked any better than regular soap and water, it’s still very widely used in other products.
Naturally, it finds its way into the human body—especially through everyday toothpaste use—with the research team pointing out that a National Health and Nutrition Examination Survey found traces of TCA in 75 percent of urine samples in American individuals. It’s among the top 10 biggest pollutants of U.S rivers.
And while it’s billed as an antibacterial that’s supposed to keep products safe from germs, triclosan is “certainly not a necessary ingredient in any consumer product.” Its use is already being phased out in many cases.
Patrick McNamara, an environmental engineer at Marquette University “There’s certainly more concern about triclosan than there is benefit, he says. “It has no added benefit in soap for washing hands. I personally avoid products that contain it, especially for my young children. The red flags around it are numerous and the benefits limited. Several hospitals have eliminated using it.