I posted studies on natto, coffee and bromelain. I know the natto and broamelain studies show how those two block the spike protein from attaching to the ACE2 receptor. Natto is available at most Korean and Japanese markets, while bromelain can be found at a better vitamin store or a Whole Foods or whatever is the equivalent of that store in your market.
https://forum.enlightenedstates.com/t/diy-health-hacks/17828