US researchers have made a step towards understanding why some natural clays are antibacterial, boosting the chances that they could one day be used as alternatives to antibiotic drugs. According to the researchers, the clays supply iron that kills bacteria by generating radicals that attack cell components.People have used clays throughout history for healing. More recently, patients in Ivory Coast suffering from a flesh-eating disease known as Buruli ulcer were treated with French green clays. The clays appeared to ease the swelling of the lesions like an antibiotic, but no-one knew how they did it.Lynda Williams and colleagues at Arizona State University in Tempe came...