medicalexpress | Non-communicable diseases including heart disease, cancer and lung
disease are now the most common causes of death, accounting for 70
percent of deaths worldwide. These diseases are considered
"non-communicable" because they are thought to be caused by a
combination of genetic, lifestyle and environmental factors and can't be
transmitted between people.
A new research paper in Science
by a team of fellows in CIFAR's Humans and the Microbiome program
throws this long-held belief into question by providing evidence that
many diseases may be transmissible between people through microbes
(including bacteria, fungi, and viruses) that live in and on our bodies.
"If our hypothesis is proven correct, it will rewrite the entire book
on public health" says B. Brett Finlay, CIFAR Fellow and professor of
microbiology at the University of British Columbia, who is lead author
on the paper.
Connecting the dots
The authors base their hypothesis on connections between three
distinct lines of evidence. First, they demonstrate that people with a
wide range of conditions, from obesity and inflammatory bowel disease to
type 2 diabetes and cardiovascular disease, have altered microbiomes.
Next, they show that altered microbiomes, when taken from diseased
people and put into animal models, cause disease. Finally, they provide
evidence that the microbiome is naturally transmissible, for example:
Spouses who share a house have more similar microbiomes than twins who
live separately.
"When you put those facts together, it points to the idea that many
traditionally non-communicable diseases may be communicable after all,"
says Finlay.
Eran Elinav, an author on the paper, CIFAR fellow, and professor at
the Weizmann Institute of Science, sees the proposed connection between
these points of evidence as an argument for thinking about disease more
broadly. "This may represent new opportunities for interventions in some
of the world's most common and bothersome diseases," he says. "We can
now think about modulating environmental factors and the microbiome, not just about targeting the human host."
