Spore breach
Multiple realities
(covers information from several alternate timelines)
A spore breach was a fictional threat of the displacement-activated spore hub drive (akin to a warp core breach) developed by Paul Stamets.
While time jumping as a result of a Krenim chronophage, Stamets repeatedly used the danger of a spore breach to quickly evacuate engineering, at one point suggesting mushrooms would grow on the engineering team's lungs. He later observed that he should be concerned his team did not know that a spore breach was not a real thing; though none of the instances permanently affected the timeline. (DIS: "Face the Strange")