The controversial food additive titanium dioxide likely has more toxic effects than previously thought, new peer-reviewed research shows, adding to growing evidence that unregulated nanoparticles used throughout the food system present an underestimated danger to consumers. “Our research highlights the detrimental effects of titanium dioxide nanoparticles as potential intestinal endocrine disruptors,” the authors wrote in the peer-reviewed study led by China’s Jiaxing Nanhu University. A 2022 lawsuit drew wide attention for alleging that Skittles are “unfit for human consumption” because they contain titanium dioxide. The new research compared the gut health of three groups: mice that were fed titanium dioxide nanoparticles, mice that were fed larger microparticles and mice that were fed no titanium dioxide. The titanium dioxide nanoparticles seemed to disrupt the enteroendocrine cells’ differentiation, which is part of the hormone secretion process, and reduce the cells’ numbers.