Welcome to the forum.
Your doc only prescribed prednisone?
No oral or rectal meds like the mesalamine based ones?
It's refreshing he's put you on gluten free, but like bananagirl mentioned, a good quality probiotic is essential IMO.
Also you may want to consider trying dairy free too.
I've been able to successfully handle my UC into remisssion through certain supplements, probiotics, diet modification (I like Paleo), and LDN - low dose naltrexone.
For more info on the protocol which has put me into remission, please go to this link: https://www.healingwell.com/community/default.aspx?f=38&m=1666318 , and look at the 11th post.
Let us know how we can help.
Rx meds didn't help me. But 4.5 mg LDN +Paleo diet +supplements=REMISSION.Protein shakes w/almond milk,Maca powder,L-Glutamine,D-Ribose,chia seeds.VSL#3,K2,VIt. D3,slippery elm bark powder.For more info,my protocol is the 11th post at this link: https://www.healingwell.com/community/default.aspx?f=38&m=1666318
If you have any questions, you can find my email address at my profile.