See a discussion of microbial nootropics at http://gnusha.org/logs/2015-06-22.log for more details.
or page 15 of the following slides http://diyhpl.us/~bryan/irc/2017-02-03-beacon.pdf#page=15
Directed evolution of microbes to engineer a nootropic
brain parasites (or perhaps intracellular parasites)
plasmids with BDNF and other neural growth factors
lots of mutagenesis
Selection methods and targets:
Maze solving: infect mice, run mice through mazes, evaluate maze solving performance, recover bacteria from the brains of mice that perform well.
Hippocampus size: infect mice, wait some time, evaluate hippocampus size, recover bacteria from mice that have larger-than-average hippocampus
Sleep: infect mice, observe sleep behavior and patterns, select for microbes that decrease total mouse sleep requirements or decrease the negative effects of sleep deprivation