Does titanium dioxide in food disrupt your gut bacteria's ability to make butyrate?

What's actually in it

Titanium dioxide (E171) is a white pigment added to candy, frosting, chewing gum, coffee creamer, and some supplements to make them look brighter. It's also in toothpaste and some medicines. The EU banned it as a food additive in 2022, but it's still legal in the U.S., Canada, and many other countries. You swallow it every time you eat a product that contains it.

What the research says

A 2026 study in J Appl Microbiol tested what titanium dioxide does to gut bacteria using an advanced colon simulation model. This model mimics the conditions inside your large intestine, complete with real human gut bacteria.

When titanium dioxide was added to the system, it changed the bacteria's behavior. One of the biggest effects was a drop in butyrate production. Butyrate is a short-chain fatty acid that your gut bacteria make when they ferment fiber. It's one of the most important compounds for colon health: it feeds the cells lining your intestine, reduces inflammation, and may protect against colon cancer.

The study found that titanium dioxide also shifted the overall bacterial community. Beneficial species declined while others increased. The metabolic output of the bacteria changed in ways that suggest worse gut health over time.

This matters because you eat titanium dioxide repeatedly, not just once. With daily exposure from multiple food sources, the effect on your gut bacteria is constant. A healthy gut needs its bacteria making butyrate at full capacity, and titanium dioxide is getting in the way.