Can someone comment on the effect of chlorinated town water on gut microbes? Would treated water have an affect as opposed to consuming rain or bore water?
Unless you are drinking a tap water (pretty extreme thing to do!), the effect is probably non-existing:
Around your parts you do not drink tap water?
Here in Germany there is a limit by law of 0.3mg per liter and most districts use between 0.03mg and 0.05mg per liter.
We drink tap water daily. There is no noticeable chlorine smell but I heard from friends their cat seems to not like it and drinks rainwater only.