Stray thought. Not trying to derail the conversation, but not sure where to put it.

There is a growing body of research about psychological effects of gut biome. Many of the cities seem to be unreachable messes. Are they tinkering with some of the biome to control the people?

https://arstechnica.com/science/2018/10/mammals-inherit-most-of-their-gut-bacteria-new-study-suggests/