Bacillus coagulans Alleviates Intestinal Damage Induced by TiO2 Nanoparticles in Mice on a High-Fat Diet

Titanium dioxide nanoparticles (TiO₂ NPs) are generally added in considerable amounts to food as a food additive. Oral exposure to TiO₂ NPs could induce intestinal damage, especially in obese individuals with a high-fat diet. The probiotic <i>Bacillus coagulans</i> (<i>B. coagulans</i>) exhibits good resistance in the gastrointestinal system and is beneficial to intestinal health. In this study, <i>B. coagulans</i> was used to treat intestinal damage caused by TiO₂ NPs in high-fat-diet mice via two intervention methods: administration of TiO₂ NPs and <i>B. coagulans</i> simultaneously and administration of TiO₂ NPs followed by that of <i>B. coagulans</i>. The intervention with <i>B. coagulans</i> was found to reduce the inflammatory response and oxidative stress. A 16S rDNA sequencing analysis revealed that <i>B. coagulans</i> had increased the diversity of gut microbiota and optimized the composition of gut microbiota. Fecal metabolomics analysis indicated that <i>B. coagulans</i> had restored the homeostasis of sphingolipids and amino acid metabolism. The intervention strategy of administering TiO₂ NPs followed by <i>B. coagulans</i> was found to be more effective. In conclusion, <i>B. coagulans</i> could alleviate intestinal damage induced by TiO₂ NPs in high-fat-diet mice TiO₂<i>B. coagulans</i>. Our results suggest a new avenue for interventions against intestinal damage induced by TiO₂ NPs.