It's common knowledge that microbes flourish in our bodies in symbiotic relationships. Now, researchers at the University of Oklahoma are saying that more comprehensive knowledge of extinct microbes may have significant implications on modern human health.
Within the gut, microbes are known to assist in human digestion, improve energy intake, produce vitamins and even help in the development of a healthy immune system.
Cecil Lewis, assistant professor in the Department of Anthropology, says that ancient DNA research can be helpful in determining whether there are certain aspects of the ecology that all humans share.
"We've introduced bacteria into our system through foods from around the world. Fruits imported from various parts of the world contribute to the global microbiomes that now inhabit our bodies," says the researcher, adding that ancient microbiome studies provide a view of these ecosystems prior to the modern world economy.
Given that the gut microbiome in living people is frequently studied using fecal samples, Lewis and his colleagues would compare two ancient coprolites, which are old dry or fossilized feces, to understand the state of microbiomes before the global world economy.
The researchers say that the c were 1,300 years old from Central Mexico, and that genetic testing determined that they were from two different people.
The team analyzed the microbiomes within the coprolites.
They claim that they have retrieved ancient DNA evidence for bacteria species similar to that seen in human microbiomes today, and characterized the functional aspects of these extinct microbiomes.
According to the group, a comparison between the two ancient samples showed them to be very similar to one another.
Lewis and his colleagues also found that the two ancient microbiomes were more similar to each other functionally than a sample of modern microbiomes.
They proposed that prehistoric microbiomes were more geographically structured than those found today, a discovery that may change the way scientists look at human microbiomes if it is proved to be true.
The researchers say that geographically structured microbiomes have ramifications for human health, for pioneering work on modern microbiomes has shown that certain bacteria can impact disease and health states, including diabetes and immune systems disorders.
Lewis says that understanding ancient microbiomes provides a better picture of microbiomes as they coadapted with our ancestors.
He admits that his findings are preliminary and that many new challenges are ahead, but insists that his research will be of interest to many, including medical professionals and biologists and the public.
"We should be thinking of ourselves as 'superorganisms' harboring microbes from around the world. This is much more complicated than just the cells that make up the body. We have more than just our body to nurture to be in good health," says Lewis.
His publication on ancient human microbiomes is available from one of the Public of Library of Science journals, PLoS ONE.