A food borne illness, also known as a food borne diesease, is an illness caused by the ingestion of toxic or infectious agents introduced by the consumption of food. Food borne illness is commonly called food poisoning, even though the physiological effects of food borne illness are not always caused by poison (toxins) content. True food poisoning occurs when a person ingests a contaminating chemical or a natural toxin, while most cases of food borne illness are caused by a variety of food borne pathogenic bacteria, viruses, prions, or parasites that contaminate food.