Can microplastics in the food chain threaten microbial food safety?
Imptox scientist, Prof. Andreja Rajkovic and his team from Ghent University published their findings in “Trends in Food Science and Technology”, presenting research on foodborne pathogens in the plastisphere.
“Plastisphere” is a relatively recent term coined by scientists to express the adaptation of microbial communities to the vast presence of plastics in our environment. Plastics colonising organisms, including bacteria and fungi, have found in plastic surfaces a new home, literally creating a new ecosystem where they interact with other organisms and their physical environment.
The story starts getting complicated when larger plastics degrade and form micro- and nanoplastics (MNPs). We know today that MNPs are present literally in every corner of our planet, including ocean and drinking water, air and soil. These tiny pieces have the capacity to enter the human organism via air, food and drinks, and anything that lives on them may be delivered into our bodies with them.
Little is known so far about the role of micro- and nanoplastics as vectors for contaminants. What happens when MNPs interact with potentially toxic biotic and abiotic materials, such as metals, allergens and pathogenic bacteria? Is there a possibility that this interaction affects bacterial virulence and threatens our food safety? What effect does the uptake of MNPs together with potentially harmful cargo material have on people's health?
These are still open questions without any definite answers. A team of Imptox researchers led by Prof. Andreja Rajkovic from Ghent University has identified major knowledge gaps in this field, highlighting the need for further studies. They conclude that “biofilm-coated MPs in foodstuffs may pose several risks to food safety, but further research will be essential to determine the extent of their effect on human health.”
Contributing authors: Raffaella Tavelli, Martijn Callens, Charlotte Grootaert, Mohamed F. Abdallah, Andreja Rajkovic
Trends in Food Science & Technology, November 2022
“Foodborne pathogens in the plastisphere: Can microplastics in the food chain threaten microbial food safety?”
Microplastics (MPs) contaminate the global marine and terrestrial ecosystems. This environmental contamination can enter the food chain, with MPs found in drinking water, fishery products and other food categories. Consequently, ingestion is considered the main route of human exposure to MPs. Concerns exist on the potential of MPs to act as vectors for pathogenic bacteria, possibly threatening microbial food safety.
Scope and approach
Starting from the current evidence on foodborne pathogens associated with MPs, we review the state of knowledge on the putative role of MPs in enhancing harmful bacterial traits and transporting them to humans. Finally, we focus on the simultaneous uptake of MPs and pathogens in the human gut.
Key findings and conclusions
Overall, we identify major knowledge gaps, both on the mechanisms and the possible health outcomes. The scarce and inconclusive results regarding the effect of MPs on microbial virulence and evolution, together with the insufficient knowledge about the attachment of microbial toxins to MPs, highlight the need for further studies. We conclude that biofilm-coated MPs in foodstuffs may pose several risks to food safety, but further research will be essential to determine the extent of their effect on human health.