Purely anecdotal, but a time ago we got some chantrelles through foraging. We've foraged for chantrelles for years, no issues. This year had been a big year, came home with maybe 25-30 lbs of chantrelles. Very good meaty chantrelles. Pickled, fried and frozen in butter, you name it. Chantrelles for weeks.
However, after our first meal, the entire house began having a phenomena where all of our poops smelled acutely like burning rubber/ burnt hair. This did not end when we stopped eating the chantrelles, and in fact has lasted for years, almost decades afterwords. Immediately afterwords it was every movement that smelled of burnt rubber/ burnt hair. Now they are relatively occasional, unless its a meal of chantrelles, in which case, its as if the event happened for the first time. I'm convinced we all experienced a shift in our gut microbiome.
I can imagine precisely what the smell they are describing smells like, and there is so much complexity we don't understand around ECM/ fungi/ plant relationships. Things like lobster mushrooms or bacterial/ fungal pathogens. Decaying permafrost and or the microbial processes that come with it.