Gut bacteria can trace human migrations

Evolution of human took million years and trillions of microbes have followed too in this journey according to a new research published recently in the journal Science. The work also highlights that we have missed many microbes too in our long evolutionary journey and some of them still inhabit in our early cousin apes. This might open gates of some human diseases as the study believes.

Researchers have been trying to find the coorelation between the gut microbes and human behaviour, disease, health, etc. But where from these microbes came?

To unveil this mystery, Andrew Moeller (currently a post doc at University of California, Berkeley) as a part of his doctoral dissertation in evolutionary biology studied gut bacteria isolated from the faeces  of 47 chimpanzees of Tanzania, 24 bonobos of Democratic Republic of Congo, 24 gorillas from Cameroon and also from 16humans of Connecticut. Moeller along with his colleagues compared the DNA sequences of every rapidly evolving genes that is common in the gut bacteria of apes and in humans. Post analysing they segregated DNA gene sequences and put into family trees.

It was found that most of the gut microbes have been residing and evolving along with us for longer time. Moeller finds two of three major families of gut bacteria from apes and humans share a common ancestor more than 15million years ago.

“It’s surprising that our gut microbes, which we could get from many sources in the environment, have actually been coevolving inside us for such a long time,” says project leader Howard Ochman, an evolutionary biologist at UT Austin to Science.

For deeper understanding in their final experiment, they looked into human microbiome by comparing DNA sequences between people from Connecticut and Malawi. It was found that bacterial strains from Africans diverged from American far about 1.7 million years ago. Moeller beliefs that gut bacteria can also be used to trace human and animal migrations.

The work “represents a significant step in understanding human microbiota coevolutionary history,” says Justin Sonnenburg of Stanford University in Palo Alto, California, who was not involved with the research. “It elegantly shows that gut microbes are passed vertically, between generations over millions of years.” Microbiologist Martin Blaser of New York University in New York City agrees: “The path of transmission was from mom apes to baby apes for hundreds of thousands of generations at least.” – Reported from Science.

Source: Science Magazine