Treating illness with milk from modified goats

Goat’s milk containing human lysozyme someday could be used to combat diarrheal illnesses among children in impoverished areas, according to researchers at the University of California-Davis.

Those researchers administered such milk to young, sick pigs in a recent study, reducing the duration and harm from a bacterial infection.

The study involved infecting young pigs with a strain of enterotoxigenic Escherichia coli and treating them with milk from the university’s Artemis line of genetically modified goats, which were developed in 1999 to carry a gene for producing human lysozyme in their milk, according to a university announcement and a scientific article published March 13, 2013, in PLoS ONE. The pigs that received the transgenic goat’s milk recovered more quickly from illness and experienced less dehydration and less damage to their intestines than did pigs fed milk from nontransgenic goats, the article states.

The researchers used young pigs for the study because of the similarities between gastrointestinal physiology in pigs and humans.

James D. Murray, PhD, a professor in the UC-Davis departments of Animal Science and Population Health and Reproduction, said lysozyme naturally produced in goat’s milk is similar to the human-type lysozyme produced by the university’s transgenic goats, but the latter tends to act more strongly as an antimicrobial. He is involved in further study to find out whether consuming milk from the modified goats is consistently effective at combating diarrheal disease.

In April, Dr. Murray was among researchers analyzing data from a study on use of the milk as a preventive measure against E coli–related disease in pigs as well as conducting experiments that used malnourished pigs as models. He noted that malnourished children are more prone to disease, which can increase the difficulty of absorbing nutrients in a spiral of declining health.

More than 1 million children die each year of diarrheal diseases, and pathogenic E coli are among the main causative agents, the article states, citing figures from a reference group of the World Health Organization and UNICEF.

“Persistent diarrhea in children that results in malnutrition can be particularly detrimental to development, leaving children with mental and growth deficiencies that can last a lifetime,” the article states.

The milk could be particularly beneficial in areas such as northern Brazil, where Dr. Murray expects the milk to eventually be used in human trials. The university is working to establish a herd of the transgenic goats in Brazil.

“The long-term goal is to move forward in Brazil, and if it works there, then hopefully the world would see that this is something useful,” he said.

The milk also could have veterinary applications, particularly for high-value animals, Dr. Murray said.

The article, “Consuming transgenic goats’ milk containing the antimicrobial protein lysozyme helps resolve diarrhea in young pigs,” is available at www.plosone.org.