About ten years ago my former PI (second author in the below paper) did quite a job on this in Burkina Faso, analyzing the composition of the gut in children living outside cities, in cities, and a comparison with European children.
Obligatory disclaimer: I was working in his laboratory at the time, but I wasn't involved in that research.
Obligatory disclaimer: I was working in his laboratory at the time, but I wasn't involved in that research.
https://www.pnas.org/doi/10.1073/pnas.1005963107