Impact of titanium dioxide nanoparticles on intestinal community in 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced acute colitis mice and the intervention effect of vitamin E

Abstract

Titanium dioxide nanoparticles (TiO₂-NPs) are widely applied as additives in foods due to their excellent whitening and brightening capability. Although the toxicity and antibacterial activity of TiO₂-NPs have been extensively studied, their impact on the gut microbiota in vivo still remains unclear, especially in animals with gastrointestinal disorders. In the present study, healthy mice and TNBS-induced colitis mice were administered with TiO₂-NPs (38.3 ± 9.3 nm) orally at a dose of 100 mg per kg bw daily for 10 days to study the impact of TiO₂-NPs on the gut microbiota and colitis development. Moreover, the mechanism of TiO₂-NPs on the gut microbiota was also discussed when the colitis mice were additionally administered with vitamin E to remove ROS. Changes in the microbiota community structure and gut-associated function prediction were analyzed through bioinformatics. The result showed that the oral administration of TiO₂-NPs mitigated colitis symptoms by reducing the DAI and CMDI scores and TNF-α level. Furthermore, 16S rDNA sequencing analysis showed that the structure and function prediction of gut microbiota could be modified in healthy mice and colitis mice after exposure to TiO₂-NPs, but the opposite physiological effect occurred since the dominant flora varied in these two groups. Moreover, vitamin E intervention did not change the effects of TiO₂-NPs on the microbiota community structure and gut-associated function, which indicates that the mechanism of the biological effects of TiO₂-NPs on the gut microbiota may not be associated with their ability to induce the generation of ROS. In summary, our work firstly found that TiO₂-NPs could regulate the gut microbiota of colitis mice and participate in the mitigation of TNBS-induced acute colitis, and the capability of TiO₂-NPs to induce the generation of ROS inducement did not contribute to this process.