Other things to consider with gut problems.

During my years as a practising, albeit non-accredited, researcher; I have found numerous disturbing phenomenon.
In one such case, I was able to culture C. Difficile with luminescent spore. The entire dish was fluorescent blue.
This was from the stool of someone with ongoing problems.

The interesting thing about this, is the likelyhood of this being a laboratory grade recombinant strain, with a luminescent tag to identify it--used for tracing.

How many other recombinant microbes end up in our gut?

I'm think specifically about e coli, because it is used to make so many different chemicals and bio-active products. It also colonizes the gut tissue--more effectively than traditional probiotics.
If it establishes, it could produce something like "insulin" ad nauseum as a gross example (unlikely) but you get the idea.

Agrobacterium is another disturbing example, because it has a plasmid capable of gene splicing, and is used routinely to genetically modify fruits and vegetables.

These are just the classic examples, I am sure they have far more categories of frankensteined microbes which MUST end up in the general environment.

Shroom