EpDis: Exogenesis

[LateArrival]

Probably neither, symbiotic stories have been done many times in science fiction literature, though to be fair I can't think of any particular stories right now in which memories of past lives are carried forwards. But if it is just between B5 and TNG, then TNG did it first with the season 4 episode The Host, which debuted the Trill. I guess technically the TNG first season episode Conspiracy also had a symbiote, but I don't think that was a co-existence with the human host, the aliens took over humans instead.

For what it is worth, tried reading up on Conspiracy Symbiotes a few years ago, and apparently they were re-written, re-imagined, or re-revised to be some group of rogue Trill-ish Symbiotes-ish or something like that.

What about Stargate SG-1 and the little guys that would make someone's eyes glow?
The Tok'ra were kind of symbiotic-ish, but came long after TNG.