Googled it and:
Gut microbiota: PAs can improve the diversity of gut microbes, and can increase the abundance of beneficial bacteria while decreasing the abundance of harmful bacteria.
Fecal odor: PAs can reduce the level of putrefactive substances in the feces, which can reduce fecal odor.
Fecal pH: PAs can decrease fecal pH.
Antimicrobial activity: PAs can have an antimicrobial effect on potentially pathogenic bacteria.
Prebiotic effect: PAs can have a prebiotic effect on beneficial bacteria.
Looks like I’m buying some seeded grapes for science!
I’d tell them to knock 50-70 off for the condition of the surfaces. No idea about the model and specs or if that’s worth it but that’s an ugly case on it and I would be grossed out using it, would probably have to tape a sheet of paper over the worn out spots to be comfortable touching that surface.