SBP 04 - Plastics in Your Food: Their Impact on Lactic Acid Bacteria Growth and Metabolic Activity

Over the years, plastics have become a major environmental concern. The global demand for plastic products has resulted in the production of 390.7 million metric tons annually (Chamas et al., 2020). As plastics accumulate, they break down into tiny fragments called microplastics (MPs), which persist in the environment for thousands of years. These tiny particles have infiltrated every corner of the world, including our food and beverages. Despite the growing prevalence of MPs in food sources, there is limited research on their direct impact on microorganisms, particularly lactic acid bacteria (LAB), which play an essential role in human health. LAB are key contributors to the gut microbiome, influencing digestion, immunity, and overall well-being. Disruptions in their populations are linked to various health conditions, making it crucial to understand how environmental factors, like MPs, may affect them (De Filippis & Pasolli, 2020).

This study aims to fill this knowledge gap by investigating the extraction, isolation, and characterization of MPs from select food items—apple, salmon, and bottled water—and assessing their impact on LAB, specifically Lactobacillus fermentum. LAB are important for gut health, and their ability to ferment lactose is an indicator of their metabolic activity, which could be altered by exposure to MPs. This research explores whether MPs in food may disrupt bacterial growth and fermentation, providing valuable insight into the potential health implications of microplastic consumption.

The motivation behind this study stems from the alarming fact that humans consume an estimated amount of microplastics equivalent to a credit card each week, according to a study funded by the WWF (2019). As plastics accumulate in the environment, their presence in food and drinks is becoming more widespread. While the long-term health effects of microplastic consumption are still largely unknown, there is growing concern about their impact on the gut microbiome. Given that the consumption of microplastics has become a global issue, it is crucial to examine their potential effects on human health, particularly in relation to chronic exposure to MPs via food.

In addition to investigating the biological effects, this study also aimed to contribute to the development of more effective techniques for isolating MPs from food products, providing valuable methodologies for future research. This could help pave the way for efforts to reduce plastic contamination in food, which in turn could support broader initiatives to decrease plastic usage in food packaging.

This investigation was then able to accomplish the following objectives:

• Extraction and Isolation of Microplastics: The study applied and modified existing techniques to extract and isolate microplastics from apple, salmon, and bottled water. A variety of separation methods were used to ensure accurate extraction and isolation from the food matrix.
• Characterization of Microplastics: The extracted MPs were confirmed and characterized through visual observations and analytical data to identify their size, shape, and composition. This step provided insights into the types of MPs found in different food samples.
• Assessment of Bacterial Growth and Metabolic Activity: The growth of Lactobacillus fermentum in the presence of microplastics was assessed by measuring bacterial growth and metabolic activity, specifically lactose fermentation. This was done to explore how MPs might affect the ability of LAB to thrive and perform essential functions related to digestion and health.

Overall, this study shed some light on the potential risks of microplastic contamination in food and its effects on the microbiome, providing a foundation for future research on how microplastics might contribute to health problems linked to gut bacteria, and ultimately offers actionable insights that can inform strategies for reducing plastic contamination in food and mitigating its impact on human health.