Esstee
I have not read any official research on this myself. Though I've seen numerous comments and articles suggesting the use of a probiotic when ingesting
Colloidal Silver .
That being said, I've been taking large amounts of CS daily and I noticed it had a definite impact on digestion and so I began taking probiotics shortly afterward. I usually take it three times per day(1/2 hour before meals). I also try and take my CS 1 hour before and 2 hours after meals so as to avoid any conflict with digestion. (don't forget to hold it under your tongue btw).
I've actually began taking two forms of CS in my own treatment. The first is an high ionic silver that I place under my tongue for about 5 mins. And the second is a metallic silver(colloidal) that I swallow. The reason for this is where ionic silver apparently doesn't do well in the stomach, whereas the metallic silver is much better suited for the stomach.
PS. I've tried numerous probiotics though the best ones seem to be those that are refrigerated(at the store). It's also important to follow a good diet when taking probiotics also(stay away from sugars, yeast products etc). Here is a source that may prove helpful:
http://www.probiotic-myths.com/default.aspx
Hope this helps.