Long-term exposure to titanium dioxide nanoparticles promotes diet-induced obesity through exacerbating intestinal mucus layer damage and microbiota dysbiosis
titanium dioxide nanoparticles, nanosafety, obesity, mucus layer, gut microbiota
Titanium dioxide nanoparticles (TiO2-NPs) are commonly used as food additives, including some high-fat foods that are risk factors for obesity. However, little is known about the effects of chronic TiO2-NPs digestion in the population on high fat diet (HFD). Herein, we reported that TiO2-NPs exacerbated HFD-induced obesity by disruption of mucus layer and alterations of gut microbiota. Oral intake of TiO2-NPs significantly increased body weight, liver weight, and amount of adipose tissues, especially in HFD-fed mice. Mechanistic studies revealed TiO2-NPs induced colonic mucus layer disruption and obesity-related microbiota dysbiosis. The damage on mucus was demonstrated through down-regulation of Muc2 gene and the absorption of mucin protein by TiO2-NPs. Consequently, mucus layer damage combined microbiota dysbiosis escalated the low-grade systemic inflammation, which exacerbated HFD-induced obesity. In contrast, gut microbiota depletion eliminated these effects, indicating gut microbiota were necessary for TiO2-NPs-induced inflammation and obesity. All the results stated the alarming role of TiO2-NPs in the HFD-driven obesity and emphasized the reevaluating the health impacts of nanoparticles commonly used in daily life, particularly, in susceptible population.
Tsinghua University Press
Xiaoqiang Zhu, Lijun Zhao, Zhi Liu, Qibing Zhou, Yanhong Zhu, Yuliang Zhao, Xiangliang Yang. Long-term exposure to titanium dioxide nanoparticles promotes diet-induced obesity through exacerbating intestinal mucus layer damage and microbiota dysbiosis. Nano Research 2021, 14(5): 1512-1522.