This project studies the influence of the Fusarium toxins deoxynivalenol, T-2 toxin, zearalenone and fumonisin B1 on the oral resorption and biotransformation mechanisms in chickens. In a first part, the influence of the disruption of the intestinal barrier at the tightjunctions on the oral resorption of mycotoxin co-contaminats and drugs will be investigated. In a second and third part, the influence on the intestinal biotransformation mechanisms and transporter proteins will be studied in the chicken. The damage to tight junctions and induction or inhibition of metabolising enzymes and P-gp efflux pups can lead to an altered oral bioavailability with consequently possible higher toxicity and higher drug residue concentrations in the edible tissues of chickens.