Yafit,
Probiotics are very helpful. ANd yes, I think if he increases his dosage, it will help him more.
Which type of Probiotic is he taking?
I like VSL#3 because its one that is especially formulated for UC, and it has 450 billion cultures in it. If you have good insurance, I would recommend your asking your doc to prescribe it for him - VSL#3 DS (double strength @ 900 billion active cultures!), and then you might only have a small copay. Perhaps you could the script written so he can use 2 packets 3 times daily?
Let us know how you make out.