system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Trek]What were the Trill like before modern medicine?

For those of you who don't remember offhand, the Trill are a joined species. A slug-like symbiote is passed from one Trill to the next collecting memories and passing on it's hosts personalities to the latest incarnation of it.  
One of the most famous examples is the Dax Symbiote who had hosts in Curzon, Jadzia and Ezri.

Now to my question; it seems that the procedure to transfer the symbiote is a pretty invasive form of surgery. How did the species deal with these operations before antibiotics?

Aditionally, how did this symbiosis originally form?
gpt
The symbiosis originally formed the same way any symbiosis does really.  We have examples on Earth to draw from.  
As for how they did it before modern medicine... well look at modern pregnancy and birth in humans.  One can be forgiven for assuming it *requires* a great deal of invasive surgery and antibiotics.  But it doesn't.  Ancient humans did just fine.  The simple matter is a lot more of them died during it.  The same is basically true for Trill.  The antibiotics and operations serve to make the process safer for all involved, but it's perfectly possible without it.