A new review authored by researchers at the Food and Agriculture Organization of the United Nations (FAO) warns that food loss and waste (FLW) may play a larger role in the spread of antimicrobial resistance (AMR) than previously recognized.

According to the authors, approximately one-third of all food produced for human consumption—totaling 1.3 billion tons—is lost or wasted each year, globally.

To understand how food that is lost or discarded across the supply chain may contribute to the spread of AMR, the FAO researchers conducted a scoping literature review. The research identified FLW as both a reservoir and a transmission route for antimicrobial resistance genes (ARGs) and antibiotic-resistant bacteria (ARB). The review also described practices that can either mitigate or exacerbate AMR dissemination from FLW.

How Food Waste Contributes to AMR

Studies have demonstrated that antibiotic residues, as well as ARB and ARGs isolated from different types of food, can be found at all stages of the agri-food system, from farm to fork, and are present in food wastes generated at those various stages. Food waste is a good substrate for bacterial growth and can foster the survival and growth of ARG-harboring bacteria. Food waste can also be further contaminated depending on waste management (i.e., collection, transportation, and pre-treatment activities).

FLW can disseminate ARB and ARGs into the environment, subsequently spreading AMR back into the agri-food system through soil, water, feed, and other routes.

Bioconversion Can Reduce AMR Under Optimal Conditions

The review found that commonly used bioconversion processes—including composting, anaerobic digestion, and conversion of FLW into animal feed—can significantly reduce ARGs and ARB. However, these reductions depend heavily on process controls such as temperature, retention time, and oxygen conditions. When these parameters are not met, end products like organic fertilizers, soil amendments, or feed materials may retain AMR risks.

Poor Disposal Practices Amplify AMR Risks

Landfilling and open dumping of FLW pose the greatest AMR risks. At the same time, most food waste around the world is still discarded in landfills.

The study notes that landfills and dumping environments often co‑contain heavy metals, microplastics, and other pollutants known to promote horizontal gene transfer. Together, these factors can enhance the survival and spread of ARB.

Additionally, leachate, aerosolization, wildlife exposure, and direct human contact were identified as potential pathways for AMR transmission from food waste streams.

Preventing AMR Spread from Food Waste

The review concludes that FLW must be explicitly recognized as a potential source of AMR and incorporated into national and global surveillance frameworks. It also emphasizes the importance of reducing antimicrobial use in agri-food production and minimizing the generation of FLW.