Using genetically modified bugs to prolong life was ‘fanciful’ until recently, says scientist
A “living medicine” made from genetically modified bugs has prolonged the lives of animals with severe metabolic disease in a landmark test of the treatment.
Researchers created the medicine by making a common strain of bacteria mop up excess ammonia in the body. High levels can be fatal for people with liver damage and rare genetic disorders.
Tests showed that the microbes reduced dangerous levels of ammonia and boosted survival rates in susceptible mice, while a small trial in healthy people found the bacteria worked as expected and were safe to take.
The breakthrough was described as “amazing” by one leading scientist who said that such medicines were considered “fanciful” only a few years ago.
“By engineering these bacteria, we are able to control how they operate in the human gastrointestinal tract,” said Caroline Kurtz at Synlogic, which was co-founded by Massachusetts Institute of Technology. “It allows us to think about many other diseases where you may need to produce something beneficial, or remove something that is toxic for the patient.”
The scientists focused on a disorder called hyperammonaemia. It occurs when levels of toxic ammonia build up in the blood and affect the brain. In mild cases people can feel sick, lose their appetite and be hard to rouse, but in severe cases it causes irreversible and sometimes fatal brain damage.
Most people who are treated for hyperammonaemia have liver damage that prevents the organ from converting ammonia in the blood into urea. But the condition also affects those with rare genetic disorders that disrupt the liver’s ability to process ammonia. About half of the ammonia circulating in the body is thought to come from bugs in the gut.