Half the cells in our body aren't human. Don't worry, these non-human cells aren't harmful. In fact, they're crucial to your health and make you, you. Trillions of bacteria, viruses and fungi flourish within us. We co-evolved with the microbial community living in our guts. Microbial signaling plays a crucial role in maintaining our health.
As our society became industrialized, we lost many microbes that once lived within us. Could any of these missing microbes help us develop new treatments?
Often, scientists look at modern hunter gatherer societies to study microbiome industrialization. Instead of relying on these humans as a proxy, scientists extracted DNA from ancient poop. It dated back between 1000 and 2000 years old, found in rock shelters in Utah and Mexico. They published their glimpse into the ancient gut microbiome in Nature in May.
In analyzing eight ancient poop samples, the researchers travelled back in time. They found overlap between modern hunter gatherer societies and the ancient poop. Roughly two of every five bacterial genomes extracted from the ancient poop were new. These never-before seen microbial species likely went extinct as we became more industrialized.
Diet is only one of many factors that changed our microbiomes. As we sequence more ancient poop, we will zero-in on the factors shaping the modern microbiome.
Scientists found so many new species in only eight samples. Of course, these samples are precious and limited. It is rare that we find these well-preserved specimens. But as out sequencing technology improves, we might be able to extract more information from ancient poop.