Some fungi are already the largest organisms on earth at >200 km^2

Armillaria ostoyae ( https://en.wikipedia.org/wiki/Armillaria_ostoyae )

Consider when organisms must pass, that these ancient fungi likely still consume the host... Thus, on a 8000 year timescale most fungi doesn't necessarily need to pursue food that naturally dies in around a century.

Yeasts are already sharing your body along with numerous other organisms that are often harmless or even beneficial. Best not think about it too much if you are uncomfortable with seeing yourself as a mini ecosystem. =3

Explainer: Armillaria ostoyae first parisitises trees and after they die (or are killed) then it shifts to a saprophytic mode to decompose the tree.

My summary after wondering why you chose the word "consume".

https://en.wikipedia.org/wiki/Armillaria_ostoyae

  rivals the aspen grove "Pando" as the known organism with the highest living biomass and perhaps rivalled by a colony of Posidonia australis on the Australian seabed that measures 200 square kilometres (edited)