Nanosized titanium dioxide (TiO₂) is a common additive in food and cosmetic products. The goal of this study was to investigate if TiO₂ nanoparticles affect intestinal epithelial tissues, normal intestinal function, or metabolic homeostasis using in vitro and in vivo methods. An in vitro model of intestinal epithelial tissue was created by seeding co-cultures of Caco-2 and HT29-MTX cells on a Transwell permeable support. These experiments were repeated with monolayers that had been cultured with the beneficial commensal bacteria Lactobacillus rhamnosus GG (L. rhamnosus). Glucose uptake and transport in the presence of TiO₂ nanoparticles was assessed using fluorescent glucose analog 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose (2-NBDG). When the cell monolayers were exposed to physiologically relevant doses of TiO₂, a statistically significant reduction in glucose transport was observed. These differences in glucose absorption were eliminated in the presence of beneficial bacteria. The decrease in glucose absorption was caused by damage to intestinal microvilli, which decreased the surface area available for absorption. Damage to microvilli was ameliorated in the presence of L. rhamnosus. Complimentary studies in Drosophila melanogaster showed that TiO₂ ingestion resulted in decreased body size and glucose content. The results suggest that TiO₂ nanoparticles alter glucose transport across the intestinal epithelium, and that TiO₂ nanoparticle ingestion may have physiological consequences.

中文翻译：

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二氧化钛纳米粒子的暴露改变了肠上皮和果蝇果蝇细胞培养模型中的代谢稳态。

纳米二氧化钛（TiO ₂）是食品和化妆品中的常见添加剂。这项研究的目的是使用体外和体内方法研究TiO ₂纳米颗粒是否影响肠上皮组织，正常肠功能或代谢稳态。的体外肠上皮组织的模型是由接种的Caco-2和HT29-MTX细胞的共培养物上的Transwell小渗透性载体创建的。用已经与有益共生细菌鼠李糖乳杆菌GG（鼠李糖乳杆菌）一起培养的单层重复这些实验。TiO ₂存在下的葡萄糖吸收和转运使用荧光葡萄糖类似物2-（N-（7-硝基苯-2-氧杂-1,3-二氮杂-4-基）氨基）-2-脱氧葡萄糖（2-NBDG）评估纳米颗粒。当细胞单层暴露于生理学相关剂量的TiO _2时，观察到葡萄糖转运的统计学显着降低。在有益细菌的存在下消除了葡萄糖吸收的这些差异。葡萄糖吸收的减少是由于肠微绒毛的损害而引起的，而肠道微绒毛的受损则减少了可吸收的表面积。鼠李糖乳杆菌的存在可减轻对微绒毛的损害。在果蝇中的免费研究表明，TiO ₂摄入会导致体重和葡萄糖含量降低。结果表明，TiO ₂纳米颗粒改变了葡萄糖跨肠上皮的运输，并且TiO ₂纳米颗粒的摄入可能会产生生理后果。