#i realized none of this answers the question of how their bacteria don't eat their own stomachs

[theoldandnewfirm]

There were a bunch of good responses to my initial post, and now that I've had a few days to noodle on them here are my thoughts.

I imagine bacteria that can break down forever plastics that quickly would be pretty valuable. @whitherwanderyouspirit

So my initial reaction was "damn, you're right," because if trolls digestion was capable of completely breaking down plastics, and scientists could isolate the bacteria that allow that, one of our major problems as a species would be solved.

So maybe plastics are more like corn in that trolls can digest some but not all of it, and what's leftover is passed through their excretory system as-is. Which would probably make Jim's first time using the bathroom as a half-troll kind of traumatic. 😆

I also like the idea of the bacteria being unable to survive outside of their digestive system. I'm thinking similar bacteria can be found in environments sustained by a heartstone, but nothing quite like the variety found in trolls (perhaps owing to them being the only omnivores in their environment).

And maybe troll tolerance for different foodstuffs varies based on what was available in their local environment, similar to how lactose intolerance is common in regions that historically didn't have cattle. You come from a tribe that wasn't near a crude oil deposit? Plastic probably won't agree with you.

Now, as for what their digestive systems look like, @slmdrs had a great idea:

Why not use goats as an example?

I think them having more of a ruminate approach to digestion could work nicely with the variety of materials they eat. It would allow things to be broken down as small as possible to make it easier/faster for their digestive system to do its thing, and allow more digestion time for materials that require it.

(On a semi-gross tangent, what if in lieu of lactation trolls fed their "cud" to whelps to help kickstart their microbiomes so they can eat the same foods the adults can?)

Now onto glug, which I spent an undue amount of time thinking about while on a plane yesterday.

Well, bacteria do multiply. Maybe trolls need to drink glug to keep the bacteria at bay, otherwise they cause troll-like heartburn or something. @nurisiliel

#glug doesn't HAVE to contain actual alcohol I think?#could be another substance that's intoxicating for trolls @undeadchestnut

Inspired by these comments, my new glug headcanon is as follows:

"Glug" is a type of tisane made from moss and intoxicating mushrooms that grow on the dung of a specific creature from the Darklands, which trolls brought with them when they moved to our world.

Most troll tribes have their own glug variants based on whatever mosses are local to their cavern. Regardless of variant, to humans glug smells like sweaty feet and has a bitterness that renders it undrinkable.

In addition, while glug isn't toxic to humans it is irritating to our digestive system, and consumption leads to explosive consequences.

Continuing my deep dive into troll speculative biology: digestion!

My first thought was they had super powerful stomach acid, but looking at the strongest known acids it seems the problem would become keeping it from eating them.

Plus, the amount of inorganic stuff they eat kept niggling at me. According to moderate googling, metals and polymers all dissolve at difference PHs, which makes stomach acid even less likely as a solution to how they digest food. In addition, extracting nutrients from inorganic material seems like a complex process that would require a lot of metabolic energy--not ideal for a large creature that would already require significant amounts of food every day to sustain itself!

So I did some more googling: what could allow trolls to digest a variety of inorganic and organic material without stomach acid and without investing in specialized systems to extract nutrients from the inorganic stuff?

My solution: bacteria! Troll stomachs are chock-full of bacterial colonies that can break down whatever the trolls ingest into nutrients for both of them.

The benefit of this is that, like snakes, they can eat a whole bunch at once and then be sustained by the bacteria slowly breaking down what they ingested over time.

Is that scientifically sound? Definitely not! Would whatever glug ruin this whole thing because alcohol is super good at killing bacteria? Probably!

But that's my current working theory. And tbh magical stomach acid is probably a better one since it requires WAY less thought than what I just made up. 😄