Research has shown that, when ingested as a food additive, titanium dioxide and its nanoparticles can impact, alter, and/or damage important protective bacteria in the gut, along with the metabolic pathways of gut bacteria.

Historical references

Titanium dioxide goes into many industrial and consumer products. It makes paper white and bright, it keeps plastics and rubber soft and flexible, and helps remove harmful emissions from car exhaust, among many other uses. In the drug industry, it's a key ingredient in pill capsules and tablet coatings to keep the medicine inside from being affected by sunlight.