Potential of Fermented Plant Extract for Removing Microplastics in Artificial Gastric and Intestinal Juices

Introduction: Microplastics (MPs) are commonly found in food and water, leading to their ingestion through daily diets. MP particles smaller than 150 μm can cross the intestinal epithelium, posing potential health risks. Rapid excretion of MPs from the intestines may help reduce these risks. Methods: Fermented plant extract (FPE) is a rich source of nutrients and active substances, which promote gut health and relieve constipation. To evaluate the MP-excluding potential of FPE, it was suspended in artificial gastric or intestinal juices, followed by the addition of 100 mg of MP particles, which remained floating in the solution. After shaking for 1 hour at 37°C, the floating MP particles were collected and weighed. The excluded weight was calculated by subtracting the weight of the floating MP particles from the initial 100 mg. Results: The weights of non-floating MP particles (diameter: 106–125 μm) in artificial gastric juice mixed with 10, 5, 2.5, and 1 g of FPE were 73 ± 0.3, 74 ± 1.7, 63 ± 1.5, and 31 ± 1.5 mg, respectively. In artificial intestinal juice, the values were 45 ± 2.3, 55 ± 1.2, 43 ± 1.2, and 16 ± 2.6 mg, respectively. The weights of non-floating particles with a diameter of 250-300 μm were significantly lower than those with a diameter of 106-125 μm. Discussion: FPE exhibited greater effectiveness in acidic gastric juice, suggesting that certain MP-binding components in FPE become ionized under acidic conditions, thereby enhancing ionic interactions with microplastics. Smaller MP particles were bound more effectively than larger ones, likely due to their relatively greater surface area. Conclusion: FPE facilitates MP exclusion from the gastrointestinal tract, reducing the risk of intestinal absorption.