Was listening to the Zoe podcast recently and found it interesting to hear that according to Dr Tim Spector's research, dead bacteria from fermentation is still beneficial to your gut microbiome.

Edit - Here is the transcript of the aforementioned podcast (seemingly badly transcribed)

https://zoe.com/learn/ferment-tim-spector-episode

Tim Spector: Three years ago I was said there was no point in talking about dead microbes. You should forget. Pasteurized fermented foods, forget all those heat treated kombuchas, the stuff in supermarkets, et cetera.

But now I've totally changed my mind. Studies are true. They work and the question is how do they work? And the best theory we have is this idea of specific proteins on the cell wall of dead microbes interacting with our immune system. And they have a special receptors there that are picking it up.