Can i take culterelle probiotic while on prednisone? will i be more likely to get an infection because weakened immune system?

Yes to both.: Can take probiotic while on prednisone. Will not make you more ill. It is questionable if helps the immune system. It may help prevent an antibiotic associated diarrhea. It depends how long you are on the prednisone. If it is long term then you can develop a weakened immune system. If not long then it is not likely to cause a major problem.