In mimosa hostilis, dmt exists in an already completed form known as Juremamamine - A molecule that looks like dmt with some bits added on.
Did you mean "complexed" and not "completed"?
Regarding Yuremamine it indeed has DMT hidden in its structure, but it is nearly impossible that it will release this as a form of free molecule while being metabolized.
A lot of other natural substances also include DMT in their structure, but this is simply due to their behaviour of being built up with tryptophane as a building block and the 2 methyl-groups just "make it look like DMT", as they are originally just carbons to elongate the structure from the amine, which acts like an anchor to build bigger structures. But in fact I really dont think that long carbon chains would ever be cleaved down to a methyl group on the N and so DMT would not be released when eating those things.
Sadly I do not have a good example, but other molecules that also "contain" DMT in their structure dont make you high on DMT either, if you eat them.
Regarding 25 g of Mimosa bark to grant you DMT-ish effects compared to 5 g + syrian rue this makes sense, as you just need a multifold higher amount of pure DMT to still make it active as you simply overshoot all your enzymes that break it down. So when not eating MAOI a very high amount of Freebase DMT still makes sense to produce effects, but again it must be very high.
On the other hand using Cyclodextrin to make DMT orally active:
I did not read much about this method, but does it really work or is it just hypothetical?
Because if you create the Cyclodextrin-DMT-complex this indeed enlarges bioactivity, which is measured as the amount of drug that finally enters the blood plasma as part of its metabolism.
And if Cyclodextrin simply helps DMT to pass the first few barriers, then there will still be MAO-Enzymes all over the body to readily catch it as soon as Cyclodextrin releases DMT. If it would want to induce an effect, DMT has to leave the complexation and then it is vulnerable to the enzymes just like before, so from my limited knowledge of Cyclodextrin I would mostly tend to say it wont help making it orally active in "normal" doses ultimately. Maybe the threshold level still sinks, as Cyclodextrin may protect DMT on the beginning of its travel through the body, nevertheless :?
Also the interesting component in Black Pepper (Piper
nigrum) = Piperin increases bioactivity, even though not as high as Cyclodextrin. Maybe combine this and even more bioactivity-enhancing agents and a possible effect will increase to a noteworthy level.