Alison,
I like the addition of the MegaSpore. I have heard of Restore Flora and HU58, but have not used them personally. They should be fine and likely a more diverse amount of bacteria to help attack the clostridia – along with the MegaSpore.
Since he handled the Biocidin well, I personally would go to 10 drops TID and repeat a Microbial Organic Acids Test (mOAT) from Great Plains Laboratory in 4 weeks to see what’s happening to the 4-cresol value. Continue with the supplements daily until lab results are back.
Regarding the HVA/DOPAC I personally would not try to intervene right now other that what you are currently doing.
Sincerely,
Dr. Woeller