General Probiotic during or after antibiotics?

Bernie started his doxycycline tonight for what could be a URI. I picked up some BeneBac for him. Is that a decent probiotic or is there something much better I could get for him? Also, one of my friends told me that you don't want to give probiotics while administering antibiotics; that you should wait until the treatment is through. That's incorrect, isn't it? I thought you gave it at the same time. I really appreciate how helpful everyone is. I still have a lot to learn!