The biomatter just gets reconstituted in the replicators. Earl Gray, anyone?
I loved the line in Discovery when they’re eating apples. “It’s made out of our shit you know. Pretty good for shit.”
Another quintessential Discovery quote…
One of the reasons I love Discovery is that it outright addresses the things that exist in the universe that are never really brought attention to otherwise. Like Klingons having two dicks. We know that they had backup organs. The dick is a reproductive organ. I mean it makes sense that there would be a backup there too, especially given the insane hostility/violence of their species. That could be talked about by fans forever and speculated on it but it was Discovery that went “Two streams, case closed.” and I fucking love them for that.