Yeast Extract is okay because the yeast has been blown apart in the making of this product instead of using them to ferment it, no actual yeast is whole and is therefore no longer the bacterial yeast.
A good example would be fearing two little ants because they may form a colony on your land, and not purchasing any compost bags or sand because there may be ants in these products. So you come here and ask whether dead ant smash paste is okay to purchase.
The answer is yes because there’s really nothing left of the infectious kind, and anyone who tells you any different needs to study microbiology.
(This may be an old topic but it came up in google and I wanted to make a point)
Except this is not applicable to many people who suffer from Candida.
You are only touching on part of the problem, what you’re ignoring are the mycotoxins.
I for example, cannot have any products that have had yeast involved, no matter if they are dead or absent in the final food product because the toxins/by-products are still present in quantities sufficient enough to trigger an immune response by my body.
This is why we are told to avoid vinegar, mushrooms, products containing lactic or citric acids because they have mycotoxins present.
There are many people who suffer from an over-reaction to yeast/yeast by-products, and they can certainly weaken our immune systems because of it, regardless of whether there are no yeast.
Plus yeast is not a bacterium, it is a fungus-based organism.
And I’d suggest you study microbiology because it’s clear you know nothing about it.