The microbes living in our gut are way less diverse than they were 2,000 years ago.
That s one of the key findings from a genomic analysis of fossilized human feces from rock shelters across North America and Mexico. Eight samples dating to between 1,000 and 2,000 years ago reveal microbes that are totally new to science, as well as others completely absent from the gut microbiome today.
By contrast, the modern gut microbiome contains vastly more antibiotic-resistant microbes than those of our ancestors. These findings could help us understand the connection - if there is one - between our diminished microbiome and the higher modern incidence of industrial chronic diseases such as diabetes and obesity.