Restraining the TiO2 nanoparticles-induced intestinal inflammation mediated by gut microbiota in juvenile rats via ingestion of Lactobacillus rhamnosus GG

Human were given a lot of opportunities to ingest TiO 2 NPs in the environment. Children have low, sensitive intestinal tolerance, and they could be exposed to higher levels of TiO 2 NPs than adults. Few studies have been conducted on the interaction between TiO 2 NPs and juvenile intestine phase models. Thus, in this work, weaning rats were orally exposed to TiO 2 NPs for 7 and 14 days. Results indicate that Ti accumulated in the intestine, liver, and feces. Inflammatory infiltration damage was observed in the colonic epithelial tissue, and gut microbiota fluctuated with a decreased abundance of Lactobacilli in feces. Oral supplementation with Lactobacillus rhamnosus GG (LGG) lessened TiO 2 NPs-induced colonic inflammatory injury, which might due to downregulation of nuclear factor kappa-B (NF-κB). Meanwhile, LGG maintained normal intestinal microbiome homeostasis, thereby improving TiO 2 NPs-induced colon injury in juvenile rats. Moreover, fecal microbiota transplant (FMT) experiment indicated possible TiO 2 NPs-induced intestinal microbiota disorder led to colonic inflammation. Our works suggested the urgent need for additional studies on the risk safety assessment, mechanism, and prevention of juvenile health damage from exposure to TiO 2 NPs.