Exposure to Titanium Dioxide Nanoparticles During Pregnancy Changed Maternal Gut Microbiota and Increased Blood Glucose of Rat

Abstract

Titanium dioxide nanoparticles (TiO2 NPs) were used worldwide for decades, and pregnant women are unable to avoid exposing to them. Studies revealed that TiO2 NPs could kill many kinds of bacteria, but whether they would affect the composition of gut microbiota, especially during pregnancy, was seldom reported. And, what adverse effects may be brought to pregnant females was also unknown. In this study, we established the prenatal exposure model of rats to explore the effects of TiO2 NPs on gut microbiota. We observed an increasing trend, but not a significant change of alpha-diversity among control and exposure groups at gestation day (GD) 10 and GD 17 during normal pregnancy process. Each different time point had unique gut microbiota operational taxonomic units (OTUs) characteristics. The abundance of Ellin6075 decreased at GD 10 and GD 17, Clostridiales increased at GD 10, and Dehalobacteriaceae decreased at GD 17 after TiO2 NPs exposure. Further phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) prediction indicated that the type 2 diabetes mellitus related genes were enhanced, and taurine metabolism was weakened at the second-trimester. Further study showed that the rats’ fasting blood glucose levels significantly increased at GD 10 (P < 0.05) and GD 17 (P < 0.01) after exposure. Our study pointed out that TiO2 NPs induced the alteration of gut microbiota during pregnancy and increased the fasting blood glucose of pregnant rats, which might increase the potential risk of gestational diabetes of pregnant women.

Foodborne Titanium Dioxide Nanoparticles Induce Stronger Adverse Effects in Obese Mice than Non‐Obese Mice: Gut Microbiota Dysbiosis, Colonic Inflammation, and Proteome Alterations

“…Several studies showed mixed results on whether TiO 2 particles modified the composition of gut microbiota, [14,[22][23][24][25] and this discrepancy may be due to multiple factors such as the difference in characteristics of TiO 2 particles, oral doses, exposure time, exposure route, and animal models. In this study, fecal pellets were freshly collected from the colon at the time of sacrifice after 8 weeks of dietary treatments with TiO 2 particle.…”

“…Some studies reported that TiO 2 NPs altered the compositions of gut microbiota and the bacterial metabolites; however, other studies reported no obvious disturbance of gut microbiota by TiO 2 NPs. [22][23][24][25] This discrepancy may be due to multiple factors such as the difference in characteristics of TiO 2 particles, oral doses, exposure time, exposure route, and animal models. It is notable that in most of these studies, TiO 2 was administered to rodents by oral gavage, a technique that has been shown to cause stress responses that may introduce a potential confounder in gut microbiome.…”

Impact of Food Additives on Gut Homeostasis

“…In addition, dietary TiO 2 dissolved in drinking water led to a decrease in mucus-related gene expression (i.e., Muc-2 ) and consequent impairment of the intestinal epithelial barrier, an increase in the antimicrobial peptide Defb3 gene expression, enhanced inflammatory response, and alteration of colonic crypt length [50]. A recent study by Mao and colleagues also investigated the impact of the exposure to TiO 2 particles in pregnant rats [51]. The authors reported a slight change in gut microbiota composition at gestation day 10 and 17 [51].…”

“…A recent study by Mao and colleagues also investigated the impact of the exposure to TiO 2 particles in pregnant rats [51]. The authors reported a slight change in gut microbiota composition at gestation day 10 and 17 [51]. In addition, fasting blood glucose levels, together with the expression of diabetes mellitus-related genes, were increased in the exposed rats [51].…”

Effects of intragastric administration of La₂O₃ nanoparticles on mouse testes

“…Nanomaterials are widely used in production and life, and can easily be released and enter human body (Mao et al, 2019;Li et al, 2018). Consequently, the risk of human exposure to La 2 O 3 NPs has increased.…”