Nanotoxicological Effects of Engineered Nanoparticles in Gastrointestinal Systems

Engineered nanoparticles (NPs) are increasingly incorporated into food additives, packaging materials and dietary supplements, leading to ubiquitous exposure via ingestion. Once in the gastrointestinal tract, NPs interact with the mucus layer, epithelial cells and resident microbiota, potentially breaching the barrier that normally prevents harmful agents from entering the circulation. Key mechanisms of toxicity include generation of reactive oxygen species, activation of pro-inflammatory signalling pathways and disruption of tight junctions, resulting in increased intestinal permeability. Concurrently, selective antimicrobial activity of certain metal-based NPs can induce dysbiosis, shifting the balance of beneficial and pathogenic bacteria and altering immune-microbiota crosstalk. Biodistribution studies indicate that a fraction of ingested NPs may translocate across the epithelium to regional lymph nodes and, occasionally, systemic tissues. Physicochemical properties such as size, shape, surface coating and dose, as well as particle ageing and transformation in digestive fluids, govern these interactions. Understanding these nanotoxicological effects is essential for risk assessment, regulatory guidance and the design of safer nanomaterials in consumer products.

Research from Nature Portfolio

Short-term oral exposure to differently shaped silver nanoparticles in a rodent model demonstrated that specific bacterial taxa are selectively depleted, with concomitant changes in exploratory behaviour. Although no overt histopathological lesions were observed in gut tissues, distinct reductions in commensal Clostridium and Bacteroides species correlated with altered anxiety-like responses, suggesting a microbiota–gut–brain axis perturbation. This work highlights how subacute nanoparticle ingestion can produce subtle but functionally significant shifts in host physiology without classic inflammatory or structural damage within the gastrointestinal tract.

Nanotoxicological Effects of Engineered Nanoparticles in Gastrointestinal Systems publication trend

The graph below shows the total number of articles in nanotoxicological effects of engineered nanoparticles in gastrointestinal systems across all publications each year (not limited to Nature Index journals).

Technical terms

Engineered nanoparticles: Materials with dimensions between 1 and 100 nm designed for specific functions in industry or medicine.
Nanotoxicology: The study of adverse biological effects elicited by nanomaterials.
Gut microbiota: The community of microorganisms residing in the gastrointestinal tract that influences host health.
Dysbiosis: A disruption of normal microbial balance, often associated with disease states.
Transepithelial electrical resistance (TEER): A quantitative measure of epithelial barrier integrity.
Reactive oxygen species (ROS): Chemically reactive molecules derived from oxygen that can damage cellular structures.
Barrier function: The ability of the intestinal epithelium to regulate passage of substances between the lumen and internal milieu.

References

1. Biodistribution and intestinal inflammatory response following voluntary oral intake of silver nanoparticles by C57BL/6J mice. Archives of Toxicology (2023).
2. Impacts of foodborne inorganic nanoparticles on the gut microbiota-immune axis: potential consequences for host health. Particle and Fibre Toxicology (2020).
3. Size and dose dependent effects of silver nanoparticle exposure on intestinal permeability in an in vitro model of the human gut epithelium. Journal of Nanobiotechnology (2016).
4. Gut Dysbiosis and Neurobehavioral Alterations in Rats Exposed to Silver Nanoparticles. Scientific Reports (2017).