A genetically engineered protein that kills parasitic intestinal worms has given researchers hope of developing a safer, more effective treatment. Scientists modified the Cry5B protein, normally produced in a bacterium not considered safe for people, and inserted it into a related bacterium commonly used in probiotic foods, successfully treating hamsters infected with the parasites. "Treatment of gut parasites has been done with highly toxic drugs so far. There is also a growing number of reports of drug resistant parasites. So it is important to have alternatives to their control," said researcher Rose Gomes Monnerat of Brazilian Agricultural Research.