Evaluation of veterinary drug residues in food for their potential to affect human intestinal microflora

The use of veterinary drugs in food-producing animals may result in trace quantities of the drugs or their metabolites being present as residues in food. The effects of veterinary drugs intended for use in food-producing animals on intestinal microflora are evaluated in drug registration since these residues may pose a risk due to their antibiotic activity. This article reviews the different in vivo and in vitro experimental test systems and approaches used by animal health industries, contract laboratories, and regulatory authorities to assess the safety of veterinary drug residues in foods for human consumption. Furthermore, we propose a systematic approach to assess the effects and safety of veterinary drug residues on the human intestinal microflora. (C) 1999 Academic Press.