Californian researchers released a report March 2013, detailing a breakthrough in their work with genetically modified goat milk with potential benefits for human health.
The researchers at the University of California, Davis said milk from goats genetically modified to produce higher levels of a human antimicrobial protein has proved effective in treating diarrhea in young pigs.
The result shows the potential for food products from transgenic animals to one day also benefit human health.
It is the first research project on record to show that goat milk carrying elevated levels of the antimicrobial lysozyme, a protein found in human breast milk, can successfully treat diarrhea caused by bacterial infection in the gastrointestinal tract.
The findings, reported in the online journal Plos One, offer hope that milk like this may eventually help prevent human diarrheal diseases that each year claim the lives of 1.8 million children around the world and impair the physical and mental development of millions more.
UC Davis animal science professor James Murray, lead researcher on the study, said many developing parts of the world rely on livestock as a main source of food.
“These results provide just one example that, through genetic engineering, we can provide agriculturally relevant animals with novel traits targeted at solving some of the health-related problems facing these developing communities,” he said.
Murray and team fed young pigs the milk from goats that were genetically modified to produce in their milk higher levels of lysozyme, a protein that naturally occurs in the tears, saliva and milk of all mammals.
Although lysozyme is produced at very high levels in human breast milk, the milk of goats and cows contains very little lysozyme, prompting the effort to boost lysozyme levels in the milk of those animals using genetic modification.
Because lysozyme limits the growth of some bacteria that cause intestinal infections and diarrhea and also encourages the growth of other beneficial intestinal bacteria, it is considered to be one of the main components of human milk that contribute to the health and well-being of breast-fed infants.
Pigs were chosen as the research model because their gastrointestinal physiology is quite similar to humans, and because pigs already produce a moderate amount of lysozyme in their milk.
Half of the pigs in the research group were fed pasteurized milk that came from the transgenic goats and carried greater amounts of lysozyme—68% of the level found in human breast milk. The other half of the pigs were fed pasteurized milk that came from non-transgenic goats and thus contained very little lysozyme.
The researchers found that, although both groups of pigs recovered from the infection and resulting diarrhea, the young pigs fed the lysozyme-rich milk recovered much more quickly than did the young pigs that received goat milk without enhanced levels of lysozyme.
Overall, the pigs fed the lysozyme milk were less dehydrated, had less intestinal inflammation, suffered less damage to the inner intestines and regained their energy more quickly than did the pigs in the control group. And, the researchers detected no adverse affects associated with the lysozyme-rich milk.
The lysozyme-enhanced milk used in the research came from a transgenic line of dairy goats developed in 1999 by Murray, co-author Elizabeth Maga and their colleagues to carry the gene for producing human lysozyme in their milk.