This Common Toothpaste Ingredient Isn’t Great for Your Gut Health, According to New Research

Even if you’re not intentionally swallowing the toothpaste on your toothbrush, its ingredients can still make their way into your bloodstream. And thus: It’s important to know what’s on that ingredient list. Despite the Food and Drug Administration (FDA) banning triclosan from soaps in 2016, it’s still found in many of the popular toothpastes on store shelves. According to a growing body of research, this might be bad news for your gut health.

Ahead, learn why triclosan is in your toothpaste, the ingredient’s potential negative effects on your gut and overall health, and how to find out if it’s in the tube in your medicine cabinet.

Why is triclosan in toothpaste?

If you took a look at your toothpaste tube right now, chances are you’d spot triclosan on the ingredient list. Found in more than 2,000 products—including antibacterial soaps, body washes, toothpastes, and even cosmetics—triclosan is a mainstay in everyday need-to-have products. “Triclosan is an ingredient added to many consumer products intended to reduce or prevent bacterial contamination,” says the FDA.

The FDA adds that one 1997 study on triclosan in Colgate toothpaste found that the product was effective at preventing gingivitis, a mild form of gum disease that causes redness and swelling. However, the FDA does not point to any other (or more recent) research that links triclosan to dental hygiene.

The potential negative impacts of triclosan

As the FDA points out, most research on the negative effects of triclosan has been conducted on animals—not human test subjects. “Some short-term animal studies have shown that exposure to high doses of triclosan is associated with a decrease in the levels of some thyroid hormones. But we don’t know the significance of those findings to human health,” says the FDA. “Other studies have raised the possibility that exposure to triclosan contributes to making bacteria resistant to antibiotics. At this time, we don’t have enough information available to assess the level of risk that triclosan poses for the development of antibiotic resistance.”

A 2017 study found that triclosan can build up and linger on your toothbrush bristles for weeks, making it simple for the ingredient to reach your gut—but some big brands didn’t regard this as a health risk. (In fact, Colgate told Time it still uses triclosan in products to “fight harmful plaque germs that can cause gingivitis.”) A year later, still more research conducted on mice and published in the journal Science Translational Medicine found that the compound could be negatively affecting your gut and putting your health at risk. And yet, things still didn’t change.

Now, a new study conducted on mice and published in the journal Nature Communications reports that triclosan can trigger inflammation in your gut. However, there’s a small ray of hope. The team of international researchers led by the University of North Carolina at Chapel Hill identified the bacteria that trigger triclosan’s harmful effects, which may have groundbreaking effects on helping those who are suffering from various gastrointestinal diseases. “By identifying the culprit bacteria, new approaches could be developed for the diagnoses, prevention and treatment of inflammatory bowel diseases,” said study author Matthew Redinbo, PhD, a chemistry and microbiology professor at the UNC-Chapel Hill College of Arts and Sciences and UNC School of Medicine, in a statement.

Now that the study authors know how to identify the bacteria that’s causes GI stress, they believe they might be able to use something called a “microbiome-targeted inhibitor” to block the unwanted effects of triclosan. They’ve done as much in mice, preventing damage to the colon and preventing symptoms of inflammatory bowel disease (IBD).

How to tell if your toothpaste contains triclosan 

While interesting, this research won’t necessarily help you “block” the potentially negative effects of consuming triclosan twice daily. (You’re brushing your teeth two times a day, right?) So if you’re thinking about swapping out your toothpaste (and other beauty products) for a triclosan-free option, here’s how to identify the ingredient in common household items.

As the FDA points out, many household brands that contain triclosan are sold over the counter. And thus, they have to list it on the “drug facts” box on the packaging. If you’re looking to eliminate triclosan from your dental hygiene products drawer, check the ingredients list.

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