A  2023 study published in the journal Environmental Research, scientists examined the effect of titanium dioxide nanoparticles on important gut bacteria in mice. Their results showed “the growth inhibitory effects could be associated with cell membrane damage caused by titanium dioxide nanoparticles to the bacterial strains. Metabolomics analysis showed that TiO2 NPs caused alterations in multiple metabolic pathways of gut bacteria, such as tryptophan and arginine metabolism, which were demonstrated to play crucial roles in regulating gut and host health.” The researchers also found that four different neuroprotective metabolites “were significantly reduced” in urine and in vitro bacteria and vivo urine samples. The researchers concluded: “Increasing evidence implies that the gut microbiome plays a profound role in regulating host metabolism. Our results illustrated that TiO2 NPs hindered the growth of four beneficial gut bacterial strains.”

Here, NaOH or NH3 · H2O is used as a precipitant or pH regulator to react with FeSO4 to form ferrous hydroxide precipitation; Air is used as oxidant; The iron sheet reacts with sulfuric acid produced during the oxidative hydrolysis of FeSO4 to provide ferrous ions required in the reaction system and maintain the pH value of the solution. The alkali consumption of acid method is less and the particles are easy to wash. The relative rates of seed preparation and crystal growth determine the particle size, particle size distribution and particle morphology of iron yellow particles.

In a statement sent to USA TODAY on Sunday, Justin Comes, vice president of research and development for Skittles maker Mars Wrigley North America, said the company couldn't comment on pending litigation – but that its use of titanium dioxide and all Mars Wrigley ingredients are safe and manufactured in compliance with strict quality and safety requirements established by food safety regulators, including the FDA.

Lithopone: an alternative to titanium dioxide