In this addendum manuscript, Fragiadakis et al. build on previous work from the lab (
Smits et al., 2017, Science) which examined seasonal variation in the gut microbiome of the Hadza hunter-gatherers from the Central Rift Valley area of Tanzania. In the current manuscript, the authors present new data suggesting that the local Hadza environment (water, bee hives, animals, etc) may serve as a reservoir of 'VANISH' taxa that are present at high relative abundance in traditional people, but which are present at a much lower relative abundance in industrialized cultures. This intriguing data suggests that the natural environment may have an important role in shaping the gut microbiome of traditional cultures. The question of whether local environment is serving as a bacterial reservoir for Hadza microbiomes, and more broadly, for populations living traditional lifestyles (as compared with the more homogenous biomes of western industrial agropastoralists) is fascinating and warrants greater consideration.