According to a new study performed by Cornell and Binghamton University, scientists have found that common metal oxide nanoparticles utilized as anti-caking and food coloring agents in the commercial ingredients industry could damage parts of the human intestine.
Cross-section of chicken intestine with cells that may be affected by food nanoparticles. Image Credit: Cornell University.
Their study was reported in the journal Antioxidants on February 9th, 2022.
We found that specific nanoparticles—titanium dioxide and silicon dioxide—ordinarily used in food may negatively affect intestinal functionality. They have a negative effect on key digestive and absorptive proteins.
Elad Tako, Study Senior Author and Associate Professor, Food Science, College of Agriculture and Life Sciences, Cornell University
In their study, the research team utilized human-relevant doses of silicon dioxide and titanium dioxide in the Tako laboratory’s in vivo system, providing a health response quite similar to that of the human body.
Into the chicken eggs, the researchers injected the nanoparticles. Once the chickens hatched, the researchers could detect changes in the morphological, functional, and microbial biomarkers present in the blood, the cecum (a pouch connected to the intestine), and the duodenum (upper intestine).
The researchers discovered changes in the composition of intestinal bacterial populations. The mineral transport of the animals was impacted and the brush border membrane (the absorptive and digestive of the surface intestine) was distressed.
We are consuming these nanoparticles on a daily basis. We don’t really know how much we consume; we don’t really know the long-term effects of this consumption. Here, we were able to demonstrate some of these effects, which is a key to understanding gastrointestinal health and development.
Elad Tako, Study Senior Author and Associate Professor, Food Science, College of Agriculture and Life Sciences, Cornell University
Tako is a faculty fellow at the Cornell Atkinson Center for Sustainability.
Besides, the group analyzed iron oxide, an iron fortification supplement, and zinc oxide, a micronutrient. Zinc oxide nanoparticles assist intestinal development, as well as a compensatory mechanism after intestinal damage. Iron oxide nanoparticles are a possible option for iron fortification via possible alterations in health and intestinal functionality.
Earlier, the Binghamton researchers performed in vitro cellular assessments and screened various nanoparticles that have been generally utilized in the pharmaceutical and food industries. The research group narrowed their study to particular metal oxide nanoparticles and guaranteed testing dosages that are suitable for humans.
“Between our two universities, our research used a nice set of systems that complement each other,” said Gretchen Mahler, Ph.D. ’08, professor of biomedical engineering at Binghamton and interim vice provost and dean of the graduate school.
Mahler stated, “We used our in vitro gut models of the small intestine to conduct assays and screen nanoparticle dosages. We then can validate what we observed in vitro by using Elad Tako’s animal model.”
The researchers are not advocating for stopping the use of such nanoparticles.
Based on the information, we suggest simply being aware. Science needs to conduct further investigations based on our findings. We are opening the door for discussion.
Elad Tako, Study Senior Author and Associate Professor, Food Science, College of Agriculture and Life Sciences, Cornell University
Besides Tako and Mahler, co-authors included Cornell doctoral candidates Jacquelyn Cheng (first author) and Nikolai Kolba; Binghamton postdoctoral fellow Alba García-Rodríguez; and Cláudia Marques, associate professor of biological sciences at Binghamton.
The study is part of the journal’s special issue on dietary supplements and oxidative stress. This study was financially supported by the National Institutes of Health.
Journal Reference:
Cheng, J., et al. (2023) Food-Grade Metal Oxide Nanoparticles Exposure Alters Intestinal Microbial Populations, Brush Border Membrane Functionality and Morphology, In Vivo (Gallus gallus). Antioxidants. doi.org/10.3390/antiox12020431.