When these mice bred, they gave birth to pups that started off with a slightly impoverished microbiome. And if those pups ate more low-fibre food too, even more microbes fell off the radar. As the generations ticked by, more and more old friends broke contact. This could explain why Westerners carry a much lower diversity of gut microbes than rural villagers from Burkina Faso, Malawi, and Venezuela.29 We not only eat fewer plants, we also heavily process the ones we do eat.
Fibre
