The more ancient human fossils we discover, the more we become acquainted with how similar our faces and bodies may have been — but what about on the inside?

Our gut and oral microbiome can have a big impact on our day-to-day health, but how have these microbial communities evolved over time and what can research into the genetics of ancient samples tell us about the modern microbiome?

Modern humans and Neanderthals not only share pieces of DNA, the composition of the microbiome in our gut is also very similar. "These bacteria were already present in the gut flora of our last common ancestor, at least 700,000 years ago."

The famous paleo diet has been around for many years, as a major current in weight loss trends. The truth is that today there are many alternative dietary guidelines, which make it overwhelming to make the best decisions. The good news is that science does not lie and is present, to help us make the best decisions.

THE MOUNTAIN OF EVIDENCE THAT MICROBES INSIDE OUR GUTS can reveal hidden details of our physical and mental health has grown a little more thanks to a new study published this month in the journal Current Biology.

ACCORDING TO PIERS MITCHELL, A paleopathologist from the University of Cambridge, scientists have been extracting data from ancient human poop for over a century. “In the past, we’ve been able to look at a single coprolite from a single person”—that is to say, a preserved turd—”and study the microbiome of that one individual.” (The microbiome is the complex collection of microbes living in every animal’s digestive tract.) Now, in a newly released paper in Philosophical Transactions B, Mitchell and co-authors Susanna Sabin and Kirsten I. Bos have blown the lid off of single-turd analysis: by analyzing two medieval latrines’ worth of number two.

It was a challenge unlike any other the chef-turned-graduate student had faced: Vayu Maini Rekdal had to create a menu in which every ingredient could be eaten either raw or cooked. No pickling was allowed, nor fermented toppings such as soy sauce or miso. Nothing could be processed, so things such as tofu were out. And the more sweet potatoes he could serve up, the better.

Before scientists tested the effects of some dietary changes on the microbiome, they ordered a special menu from a chef-turned-chemist.