Brazilian and UC Davis scientists James Murray and Elizabeth Maga are teaming up to develop a herd of genetically modified dairy goats, whose milk could protect against diarrhea, a major killer of the children around the world.
The goats will produce the human enzyme lysozyme, a natural anti-bacterial substance found in tears, saliva and human breast milk. The team plans to establish the herd in Brazil within two years and hopes to begin human trials with the genetically enhanced goats’ milk within three to five years.
The new project, funded with a $3.1 million grant from Brazil’s Ministry of Science and Technology, is lead by Aldo Lima, professor and director of the Clinical Research Unit and Institute of Biomedicine at the Federal University of Ceará, in Forteleza, Brazil.
During the past 10 years, Maga and Murray have developed a herd of genetically modified dairy goats at UC Davis and studied how the beneficial properties of human milk might be introduced into the milk of dairy goats. In a paper published last year in the Journal of Nutrition, they showed that pigs fed with milk from the GM goats were better able to resist bacterial infection.
Their research has shown that dairy goats can be genetically engineered to carry the human gene that causes them to produce elevated levels of lysozyme in their milk. Furthermore, they have shown that pigs that were fed the lysozyme-rich milk were better able to fend off bacterial infections than were those animals that were fed goats’ milk that did not contain the human enzyme.
“We all consume lysozyme in our saliva every time we swallow,” Murray said. “By increasing lysozyme levels in goats’ milk, we are simply providing more of a healthful protein that poses no toxic or allergenic problems.”
Providing the bridge between the scientists in Brazil and the United States are two former UC Davis animal science graduates and postdoctoral fellows, Marcelo Bertolini and his wife, Luciana Bertolini, both now faculty members at the University of Forteleza.
The long-term goal for the project, which would require renewed funding after three years, is to determine whether the lysozyme-rich goats’ milk offers a safe and efficient method for preventing and treating diarrheal diseases in people. After extensive studies in the lab and using animal models, the goats’ milk carrying enhanced levels of lysozyme would be provided to children from some of the Brazilian communities that are plagued by diarrheal diseases.