A family tree showing how different strains of Bifidobacteriaceae bacteria evolved in humans [blue] and our hominid relatives, the gorilla [green], chimp [yellow] and bonobo [red].
We’ve been posting quite a bit about the critters inside us, organisms that comprise the majority of the cells inside our skins.
They’ve been linked with a growing list of human afflictions, as we’ve noted in previous posts about Previous posts have noted newly established links between our intestinal microbes and multiple sclerosis, rheumatoid arthritis, chronic fatigue syndrome, anorexia, Alzheimer’s disease, and even our emotional states.
And now comes the latest intestinal microbial discovery, genetic traits they share in large part with their relatives in the guts of our own relatives.
From the University of California, Berkeley: [emphasis added]
For all the anxiety today about the bacteria in our gut being under constant assault by antibiotics, stress and bad diets, it turns out that a lot of the bacteria in our intestines have been with us for at least 15 million years, since we were pre-human apes.
A new comparison [$30 for a one-day access] of the gut microbiomes of humans, chimps (our closest ancestor), bonobos and gorillas shows that the evolution of two of the major families of bacteria in these apes’ guts exactly parallels the evolution of their hosts.
This shows that the microbes in our guts are determined in part by our evolutionary history, not just external factors like diet, medicine and geography. Obesity, cancer and some inflammatory diseases, such as diabetes and Crohn’s disease, have been linked to imbalances in the mix of microbes in our stomach and intestines.
“We are showing that some human gut bacteria are the direct descendant of gut bacteria that lived within our common ancestors with apes,” said lead researcher Andrew Moeller, a Miller Postdoctoral Fellow in UC Berkeley’s Museum of Vertebrate Zoology. “It shows there has been an unbroken line of inheritance or transfer from one generation to another for millions of years, since the dawn of African apes.”
Moeller is beginning to assemble a snapshot of the microbes in the guts of our ancient ape ancestor — in essence, a paleo gut that fit our paleo diet — and hopes to go even further back in time if, as seems likely, all mammals have evolved their unique microbiota from a common ancestral population in the distant past.
“We now have samples from all the major groups of mammals, and we’re working on tracing the evolution of the microbiome all the way back to when we were tiny carnivorous creatures 100 million years ago,“ he said.
There’s more, after the jump. Continue reading