The western diet contains processed food made of many additives such as emulsifiers and colouring agents. Among them is the titanium dioxide nanoparticle (nTiO2) also called E171. In average 2mg per kg per day of nTiO2 are consumed in the western world, yet its impact on health has not been fully defined. Preclinical study suggests that nTiO2 exacerbate colorectal cancer and colitis in mice suggesting a potential effect on the immune system.

The aim of this study is to define how dietary nTiO2 impacts on mouse immunity.

Mice were treated for 4 weeks with 0, 2, 10 or 50mg/kg per day of nTiO2. Body weight, food and water intake were measured. Myeloid (monocytes, macrophages, dendritic cells and NK cells) and lymphoid (CD4, CD8 T cells, regulatory T cells and Th17 cells) immune cells were assessed by flow cytometry in the colon, mesenteric lymph nodes, spleen and inguinal lymph nodes.

In conclusion key subsets of immune cells were affected by consumption of nTiO2 suggesting a potential detrimental impact of this common product on health.