Bacteria is all around us, on top of us, and even inside us, but did you know some of that bacteria has been passed down to us for millions of years?
The bacteria inside our guts has been there since before we were born and has been coevolving with hominids for millions of years, according to a new study published in Science.
We, along with apes, have a micro biome comprised of a collection of bacteria that’s living inside our guts, but it has long been unclear whether these microbes are coming from our environment or our ancestors.
To answer that question, a team of international scientists began to study poop. They isolated bacteria from fecal matter that came from chimpanzees in Tanzania, bonobos in the Democratic Republic of the Congo, gorillas in Cameroon, and humans from Connecticut.
Science reports that from the samples they collected they compared the DNA sequences of a single rapidly evolving gene common in the gut of apes, including humans. The DNA gene sequences were then sorted out into family trees.
The study found that two of the three major gut bacteria in apes and humans arose from an ancient bacteria that lived in the guts of our ancestors, suggesting that evolution plays a bigger role than was previously thought in the makeup of our intestinal micro biomes.
“Gut bacteria therefore are not simply acquired from the environment, but have coevolved for millions of years with hominids to help shape our immune systems and development,” the study says.
To break it down, Science says that “as the different species of apes diverged from this ancestor, their gut bacteria also split into new strains, and coevolved in parallel…to adapt to differences in the diets, habitats, and diseases in the gastrointestinal tracts of their hosts.”
It turns out that the bacteria in our guts has existed over a span of more than 15 million years of evolution and will continue to be passed on.
To learn more about this study, you can read the article from Science.