Changes of various insecticides during in vitro human digestion

Area of Science:

• Environmental Chemistry
• Toxicology
• Microbiology

Background:

• Pesticide residues in food pose potential health risks.
• Understanding pesticide degradation during digestion is crucial for risk assessment.
• Insecticides like DDT, DDD, DDE, bifenthrin, and fipronil are commonly found in the environment.

Purpose of the Study:

• To investigate the impact of in vitro human digestion on the concentrations of five specific insecticides.
• To evaluate the role of different digestive stages and enteric bacteria in insecticide degradation.

Main Methods:

• Utilized an in vitro human digestion model simulating mouth, stomach, small intestine, and large intestine conditions.
• Incorporated specific enteric bacteria, Lactobacillus sakei and Escherichia coli, in the large intestine phase.
• Quantified the concentrations of DDT, DDD, DDE, bifenthrin, and fipronil at various digestion steps.

Main Results:

• Concentrations of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD), 2,2-bis(p-chlorophenyl)-1,1-dichloroethylene (DDE), and bifenthrin decreased progressively throughout digestion.
• 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) and fipronil concentrations remained stable until the small intestine stage.
• All tested insecticides showed significant reduction during large intestinal digestion, particularly in the presence of enteric bacteria.

Conclusions:

• In vitro human digestion leads to a decrease in the concentrations of the studied insecticides.
• Enteric bacteria significantly contribute to the degradation of these insecticides during the large intestinal digestion phase.
• These findings have implications for understanding pesticide bioavailability and human exposure.